CVE-2026-31789

Aliases:UBUNTU-CVE-2026-31789DEBIAN-CVE-2026-31789ALPINE-CVE-2026-31789CGA-4pxx-5wwr-cqffCGA-mfrg-992g-qvmrCGA-mhv9-p53w-vxw8CGA-3hrp-6vj7-r4c7CGA-9cgr-6pxh-qgqqCGA-h39w-8ch7-c6pvCGA-jjxq-w2c3-9p43CGA-m365-wpjc-hx7wCGA-q4g6-qp9h-27mpCGA-qg8m-w258-82cgCGA-qrxp-mx3f-542fCGA-rhpm-jf4w-474xCGA-x4mm-f7hr-pgvxCGA-xpf4-286g-62fj
Advisory lineage Upstream: 0 Downstream: 24
Modified
Published: 07 Apr 2026, 22:00
Last modified:12 May 2026, 12:09

Vulnerability Summary

Overall Risk (default)
high
70/100
CVSS Score
9.8 CRITICAL
v3.1 (nvd)
EPSS Score
0.24% LOW
0% probability +0.02%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

07 Apr 2026, 22:00
Published
Vulnerability first disclosed
12 May 2026, 12:09
Last Modified
Vulnerability information updated

Description

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.

CVSS Metrics

  • v3.1•CRITICAL•Score: 9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
  • v3.1•MEDIUM•Score: 5.8CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:H

EPSS Trends

Current EPSS score: 0.24%• Percentile: 16%

Techniques & Countermeasures

  • CWE-787•Out-of-bounds Write

    The product writes data past the end, or before the beginning, of the intended buffer.

Affected Systems

  • alpine•openssl

    ≥ 3.0.0, < 3.3.7-r0 | ≥ 3.0.0, < 3.3.7-r0 | ≥ 3.0.0, < 3.5.6-r0 | ≥ 3.0.0, < 3.5.6-r0 | ≥ 3.0.0, < 3.5.6-r0

  • chainguard•libcrypto3

    < 3.6.2-r0

  • chainguard•libcrypto3-2.34

    < 3.6.2-r0

  • chainguard•openssl

    < 3.6.2-r0

  • chainguard•openssl-provider-fips-3.4.0

    < 0

  • chainguard•openssl-provider-fips-3.4.0-dbg

    < 0

  • chainguard•openssl-provider-fips-3.6.0

    < 0

  • chainguard•openssl-provider-fips-3.6.0-dbg

    < 0

  • wolfi•libcrypto3

    < 3.6.2-r0

  • wolfi•openssl

    < 3.6.2-r0

  • debian•openssl

    < 3.0.19-1~deb12u2 | < 3.5.5-1~deb13u2 | < 3.6.2-1

  • ubuntu•edk2

    all | all | all

  • ubuntu•edk2-hwe

    all

  • ubuntu•openssl

    < 3.0.2-0ubuntu1.23 | all | < 3.0.13-0ubuntu3.9 | < 3.5.3-1ubuntu3.3 | < 3.5.5-1ubuntu3

  • ubuntu•openssl-fips

    all | < 3.0.13-0ubuntu3.12+Fips1

  • openssl•openssl

    ≥ 3.0.0, < 3.0.20 | ≥ 3.3.0, < 3.3.7 | ≥ 3.4.0, < 3.4.5 | ≥ 3.5.0, < 3.5.6 | ≥ 3.6.0, < 3.6.2

References (15)