CVE-2026-31789 (GCVE-0-2026-31789)

Vulnerability from cvelistv5 – Published: 2026-04-07 22:00 – Updated: 2026-04-09 03:56
VLAI?
Title
Heap Buffer Overflow in Hexadecimal Conversion
Summary
Issue summary: Converting an excessively large OCTET STRING value to a hexadecimal string leads to a heap buffer overflow on 32 bit platforms. Impact summary: A heap buffer overflow may lead to a crash or possibly an attacker controlled code execution or other undefined behavior. If an attacker can supply a crafted X.509 certificate with an excessively large OCTET STRING value in extensions such as the Subject Key Identifier (SKID) or Authority Key Identifier (AKID) which are being converted to hex, the size of the buffer needed for the result is calculated as multiplication of the input length by 3. On 32 bit platforms, this multiplication may overflow resulting in the allocation of a smaller buffer and a heap buffer overflow. Applications and services that print or log contents of untrusted X.509 certificates are vulnerable to this issue. As the certificates would have to have sizes of over 1 Gigabyte, printing or logging such certificates is a fairly unlikely operation and only 32 bit platforms are affected, this issue was assigned Low severity. The FIPS modules in 3.6, 3.5, 3.4, 3.3 and 3.0 are not affected by this issue, as the affected code is outside the OpenSSL FIPS module boundary.
Severity ?
No CVSS data available.
CWE
Assigner
References
Impacted products
Vendor Product Version
OpenSSL OpenSSL Affected: 3.6.0 , < 3.6.2 (semver)
Affected: 3.5.0 , < 3.5.6 (semver)
Affected: 3.4.0 , < 3.4.5 (semver)
Affected: 3.3.0 , < 3.3.7 (semver)
Affected: 3.0.0 , < 3.0.20 (semver)
Create a notification for this product.
Date Public ?
2026-04-07 14:00
Credits
Quoc Tran (Xint.io - US Team) Igor Ustinov
Show details on NVD website
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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
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  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Detection rules are retrieved from Rulezet.