{"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": "2026-04-07T22:00:54.983Z"}, "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"}}}}

{}

{"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": "2026-04-07T22:16:21.617", "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": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-787"}], "source": "openssl-security@openssl.org", "type": "Secondary"}]}

{}

{}