{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-31789", "assignerOrgId": "3a12439a-ef3a-4c79-92e6-6081a721f1e5", "state": "PUBLISHED", "assignerShortName": "openssl", "dateReserved": "2026-03-09T15:56:53.191Z", "datePublished": "2026-04-07T22:00:54.983Z", "dateUpdated": "2026-04-13T13:04:17.163Z"}, "containers": {"cna": {"affected": [{"defaultStatus": "unaffected", "product": "OpenSSL", "vendor": "OpenSSL", "versions": [{"lessThan": "3.6.2", "status": "affected", "version": "3.6.0", "versionType": "semver"}, {"lessThan": "3.5.6", "status": "affected", "version": "3.5.0", "versionType": "semver"}, {"lessThan": "3.4.5", "status": "affected", "version": "3.4.0", "versionType": "semver"}, {"lessThan": "3.3.7", "status": "affected", "version": "3.3.0", "versionType": "semver"}, {"lessThan": "3.0.20", "status": "affected", "version": "3.0.0", "versionType": "semver"}]}], "credits": [{"lang": "en", "type": "reporter", "value": "Quoc Tran (Xint.io - US Team)"}, {"lang": "en", "type": "remediation developer", "value": "Igor Ustinov"}], "datePublic": "2026-04-07T14:00:00.000Z", "descriptions": [{"lang": "en", "supportingMedia": [{"base64": false, "type": "text/html", "value": "Issue summary: Converting an excessively large OCTET STRING value to<br>a hexadecimal string leads to a heap buffer overflow on 32 bit platforms.<br><br>Impact summary: A heap buffer overflow may lead to a crash or possibly<br>an attacker controlled code execution or other undefined behavior.<br><br>If an attacker can supply a crafted X.509 certificate with an excessively<br>large OCTET STRING value in extensions such as the Subject Key Identifier<br>(SKID) or Authority Key Identifier (AKID) which are being converted to hex,<br>the size of the buffer needed for the result is calculated as multiplication<br>of the input length by 3. On 32 bit platforms, this multiplication may overflow<br>resulting in the allocation of a smaller buffer and a heap buffer overflow.<br><br>Applications and services that print or log contents of untrusted X.509<br>certificates are vulnerable to this issue. As the certificates would have<br>to have sizes of over 1 Gigabyte, printing or logging such certificates<br>is a fairly unlikely operation and only 32 bit platforms are affected,<br>this issue was assigned Low severity.<br><br>The FIPS modules in 3.6, 3.5, 3.4, 3.3 and 3.0 are not affected by this<br>issue, as the affected code is outside the OpenSSL FIPS module boundary."}], "value": "Issue summary: Converting an excessively large OCTET STRING value to\na hexadecimal string leads to a heap buffer overflow on 32 bit platforms.\n\nImpact summary: A heap buffer overflow may lead to a crash or possibly\nan attacker controlled code execution or other undefined behavior.\n\nIf an attacker can supply a crafted X.509 certificate with an excessively\nlarge OCTET STRING value in extensions such as the Subject Key Identifier\n(SKID) or Authority Key Identifier (AKID) which are being converted to hex,\nthe size of the buffer needed for the result is calculated as multiplication\nof the input length by 3. On 32 bit platforms, this multiplication may overflow\nresulting in the allocation of a smaller buffer and a heap buffer overflow.\n\nApplications and services that print or log contents of untrusted X.509\ncertificates are vulnerable to this issue. As the certificates would have\nto have sizes of over 1 Gigabyte, printing or logging such certificates\nis a fairly unlikely operation and only 32 bit platforms are affected,\nthis issue was assigned Low severity.\n\nThe FIPS modules in 3.6, 3.5, 3.4, 3.3 and 3.0 are not affected by this\nissue, as the affected code is outside the OpenSSL FIPS module boundary."}], "metrics": [{"format": "other", "other": {"content": {"text": "Low"}, "type": "https://openssl-library.org/policies/general/security-policy/"}}], "problemTypes": [{"descriptions": [{"cweId": "CWE-787", "description": "CWE-787 Out-of-bounds Write", "lang": "en", "type": "CWE"}]}], "providerMetadata": {"orgId": "3a12439a-ef3a-4c79-92e6-6081a721f1e5", "shortName": "openssl", "dateUpdated": "2026-04-07T22:00:54.983Z"}, "references": [{"name": "OpenSSL Advisory", "tags": ["vendor-advisory"], "url": "https://openssl-library.org/news/secadv/20260407.txt"}, {"name": "3.6.2 git commit", "tags": ["patch"], "url": "https://github.com/openssl/openssl/commit/a24216018e1ede8ff01a4ff5afff7dfbd443e2f9"}, {"name": "3.5.6 git commit", "tags": ["patch"], "url": "https://github.com/openssl/openssl/commit/945b935ac66cc7f1a41f1b849c7c25adb5351f49"}, {"name": "3.4.5 git commit", "tags": ["patch"], "url": "https://github.com/openssl/openssl/commit/364f095b80601db632b0def6a33316967f863bde"}, {"name": "3.3.7 git commit", "tags": ["patch"], "url": "https://github.com/openssl/openssl/commit/7a9087efd769f362ad9c0e30c7baaa6bbfa65ecf"}, {"name": "3.0.20 git commit", "tags": ["patch"], "url": "https://github.com/openssl/openssl/commit/a91e537d16d74050dbde50bb0dfb1fe9930f0521"}], "source": {"discovery": "UNKNOWN"}, "title": "Heap Buffer Overflow in Hexadecimal Conversion", "x_generator": {"engine": "Vulnogram 0.2.0"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-31789", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-04-09T03:56:05.246752Z"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-04-13T13:04:17.163Z"}}]}}

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On 32 bit platforms, this multiplication may overflow\nresulting in the allocation of a smaller buffer and a heap buffer overflow.\n\nApplications and services that print or log contents of untrusted X.509\ncertificates are vulnerable to this issue. 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On 32 bit platforms, this multiplication may overflow<br>resulting in the allocation of a smaller buffer and a heap buffer overflow.<br><br>Applications and services that print or log contents of untrusted X.509<br>certificates are vulnerable to this issue. As the certificates would have<br>to have sizes of over 1 Gigabyte, printing or logging such certificates<br>is a fairly unlikely operation and only 32 bit platforms are affected,<br>this issue was assigned Low severity.<br><br>The FIPS modules in 3.6, 3.5, 3.4, 3.3 and 3.0 are not affected by this<br>issue, as the affected code is outside the OpenSSL FIPS module boundary.", "base64": false}]}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-787", "description": "CWE-787 Out-of-bounds Write"}]}], "providerMetadata": {"orgId": "3a12439a-ef3a-4c79-92e6-6081a721f1e5", "shortName": "openssl", "dateUpdated": "2026-04-07T22:00:54.983Z"}}}, "cveMetadata": {"cveId": "CVE-2026-31789", "state": "PUBLISHED", "dateUpdated": "2026-04-13T13:04:17.163Z", "dateReserved": "2026-03-09T15:56:53.191Z", "assignerOrgId": "3a12439a-ef3a-4c79-92e6-6081a721f1e5", "datePublished": "2026-04-07T22:00:54.983Z", "assignerShortName": "openssl"}, "dataVersion": "5.2"}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "Issue summary: Converting an excessively large OCTET STRING value to\na hexadecimal string leads to a heap buffer overflow on 32 bit platforms.\n\nImpact summary: A heap buffer overflow may lead to a crash or possibly\nan attacker controlled code execution or other undefined behavior.\n\nIf an attacker can supply a crafted X.509 certificate with an excessively\nlarge OCTET STRING value in extensions such as the Subject Key Identifier\n(SKID) or Authority Key Identifier (AKID) which are being converted to hex,\nthe size of the buffer needed for the result is calculated as multiplication\nof the input length by 3. On 32 bit platforms, this multiplication may overflow\nresulting in the allocation of a smaller buffer and a heap buffer overflow.\n\nApplications and services that print or log contents of untrusted X.509\ncertificates are vulnerable to this issue. As the certificates would have\nto have sizes of over 1 Gigabyte, printing or logging such certificates\nis a fairly unlikely operation and only 32 bit platforms are affected,\nthis issue was assigned Low severity.\n\nThe FIPS modules in 3.6, 3.5, 3.4, 3.3 and 3.0 are not affected by this\nissue, as the affected code is outside the OpenSSL FIPS module boundary."}], "id": "CVE-2026-31789", "lastModified": "2026-04-08T21:27:00.663", "metrics": {}, "published": "2026-04-07T22:16:21.617", "references": [{"source": "openssl-security@openssl.org", "url": "https://github.com/openssl/openssl/commit/364f095b80601db632b0def6a33316967f863bde"}, {"source": "openssl-security@openssl.org", "url": "https://github.com/openssl/openssl/commit/7a9087efd769f362ad9c0e30c7baaa6bbfa65ecf"}, {"source": "openssl-security@openssl.org", "url": "https://github.com/openssl/openssl/commit/945b935ac66cc7f1a41f1b849c7c25adb5351f49"}, {"source": "openssl-security@openssl.org", "url": "https://github.com/openssl/openssl/commit/a24216018e1ede8ff01a4ff5afff7dfbd443e2f9"}, {"source": "openssl-security@openssl.org", "url": "https://github.com/openssl/openssl/commit/a91e537d16d74050dbde50bb0dfb1fe9930f0521"}, {"source": "openssl-security@openssl.org", "url": "https://openssl-library.org/news/secadv/20260407.txt"}], "sourceIdentifier": "openssl-security@openssl.org", "vulnStatus": "Awaiting Analysis", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-787"}], "source": "openssl-security@openssl.org", "type": "Secondary"}]}

{"bugzilla": {"description": "openssl: OpenSSL: Heap buffer overflow on 32-bit systems from large X.509 certificate processing", "id": "2451095", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2451095"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.8", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:H", "status": "draft"}, "cwe": "CWE-190", "details": ["A flaw was found in OpenSSL. This vulnerability, a heap buffer overflow, affects 32-bit systems when processing an unusually large X.509 certificate. If an application or service attempts to print or log such a specially crafted certificate, it could lead to a system crash or potentially allow an attacker to execute arbitrary code. This issue is considered low severity due to the specific conditions required for exploitation, including the need for an extremely large certificate and a 32-bit operating environment."], "mitigation": {"lang": "en:us", "value": "To mitigate this issue, avoid processing or logging untrusted X.509 certificates, particularly those with unusually large OCTET STRING values. Restricting the source of X.509 certificates to trusted entities can reduce exposure to this vulnerability."}, "name": "CVE-2026-31789", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Fix deferred", "package_name": "edk2", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Fix deferred", "package_name": "openssl", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Fix deferred", "package_name": "shim", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Fix deferred", "package_name": "shim-unsigned-aarch64", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Fix deferred", "package_name": "shim-unsigned-x64", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Fix deferred", "package_name": "openssl", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Fix deferred", "package_name": "openssl", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Fix deferred", "package_name": "ovmf", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "compat-openssl10", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "edk2", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "mingw-openssl", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "openssl", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "shim", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "shim-unsigned-x64", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "compat-openssl11", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "edk2", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "openssl", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "shim", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "shim-unsigned-aarch64", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "shim-unsigned-x64", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Affected", "package_name": "openssl", "product_name": "Red Hat Hardened Images"}, {"cpe": "cpe:/a:redhat:jboss_core_services:1", "fix_state": "Fix deferred", "package_name": "openssl", "product_name": "Red Hat JBoss Core Services"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Fix deferred", "package_name": "rhcos", "product_name": "Red Hat OpenShift Container Platform 4"}], "public_date": "2026-04-07T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-31789\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-31789"], "statement": "This issue has a Low impact. The vulnerability affects 32-bit systems and requires an application or service to process an unusually large X.509 certificate (over 1 Gigabyte) by printing or logging its contents. This specific condition makes exploitation unlikely in typical Red Hat environments.", "threat_severity": "Low"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[3.6.0,3.6.2)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[3.5.0,3.5.6)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[3.4.0,3.4.5)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[3.3.0,3.3.7)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[3.0.0,3.0.20)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "OpenSSL", "source": "cna", "vendor": "OpenSSL"}, "product": "openssl", "vendor": "openssl"}], "analysis": {"en": {"generated_at": "2026-04-13T13:51:25.801409+00:00", "value": {"mitigation_remediation": ["Update OpenSSL to a version that includes the patch commits referenced in the advisory", "If an immediate update is not possible, reject or skip processing of certificates with excessively large extensions before the hex conversion step", "Disable logging or printing of certificate contents for untrusted certificates", "Avoid running the application on a 32\u2011bit architecture or enforce strict heap allocation limits", "Review and strengthen certificate validation logic to reject oversized OCTET STRING values"], "summary": {"action": "Patch", "impact": "Heap buffer overflow via malformed X.509 certificates could lead to a crash or potential code execution on 32\u2011bit OpenSSL systems."}, "threat_synthesis": {"affected_systems": "All OpenSSL distributions that compile the affected X.509 conversion code for 32\u2011bit architectures are vulnerable. The FIPS modules in versions 3.0 through 3.6 are not affected because the corrupted code lies outside the FIPS boundary. Exact version numbers are not listed in the advisory, so any release preceding the patch commits referenced in the advisory is considered at risk.", "description_and_impact": "Converting an excessively large OCTET STRING from an X.509 certificate to a hexadecimal string uses the input length multiplied by three. On 32\u2011bit platforms this multiplication can overflow, causing an undersized buffer to be allocated on the heap. When extensions such as the Subject Key Identifier or Authority Key Identifier contain such a large value, the resulting buffer overflow may terminate the process or, under specific attacker\u2011controlled conditions, trigger arbitrary code execution. The vulnerability is tied to the X.509 conversion routine and only manifests when an unusually large extension is supplied.", "risk_and_exploitability": "The CVSS score of 5.8 indicates low severity, while the EPSS score of less than 1% suggests a very low likelihood of exploitation in the wild. The vulnerability is not catalogued in CISA\u2019s KEV list, further supporting its low risk profile. Exploitation would require an attacker to supply an X.509 certificate with an OCTET STRING over 1\u202fGB, a scenario inferred from the description and unlikely under normal operation. Consequently the risk of inadvertent or malicious exploitation is minimal but the presence of a heap overflow warrants remediation."}}}}, "created": "2026-04-08T19:33:53.554008+00:00", "updated": "2026-04-13T14:27:10.793175+00:00", "vendors": ["openssl", "openssl$PRODUCT$openssl"]}