CVE-2026-31789Out-of-bounds Write in Openssl

Severity
5.8MEDIUM
No vector
EPSS
0.0%
top 98.43%
CISA KEV
Not in KEV
Exploit
No known exploits
Timeline
PublishedApr 7
Latest updateApr 9

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 t

Affected Packages5 packages

debiandebian/openssl< openssl 3.0.19-1~deb12u2 (bookworm)
CVEListV5openssl/openssl3.6.03.6.2+4
Alpineopenssl/openssl< 3.5.6-r0+1
Debianopenssl/openssl< 3.0.19-1~deb12u2+1

🔴Vulnerability Details

3
GHSA
GHSA-j79m-9jxq-788r: Issue summary: Converting an excessively large OCTET STRING value to a hexadecimal string leads to a heap buffer overflow on 32 bit platforms2026-04-08
OSV
CVE-2026-31789: Issue summary: Converting an excessively large OCTET STRING value to a hexadecimal string leads to a heap buffer overflow on 32 bit platforms2026-04-07
OSV
CVE-2026-31789: Issue summary: Converting an excessively large OCTET STRING value to a hexadecimal string leads to a heap buffer overflow on 32 bit platforms2026-04-07

📋Vendor Advisories

5
Ubuntu
OpenSSL vulnerabilities2026-04-09
Ubuntu
OpenSSL vulnerabilities2026-04-08
Red Hat
openssl: OpenSSL: Heap buffer overflow on 32-bit systems from large X.509 certificate processing2026-04-07
Microsoft
Heap Buffer Overflow in Hexadecimal Conversion2026-04-02
Debian
CVE-2026-31789: openssl - Issue summary: Converting an excessively large OCTET STRING value to a hexadecim...2026

🕵️Threat Intelligence

8
Wiz
CVE-2026-28388 Impact, Exploitability, and Mitigation Steps | Wiz
Wiz
CVE-2026-28386 Impact, Exploitability, and Mitigation Steps | Wiz
Wiz
CVE-2026-28387 Impact, Exploitability, and Mitigation Steps | Wiz
Wiz
CVE-2026-28389 Impact, Exploitability, and Mitigation Steps | Wiz
Wiz
CVE-2026-28390 Impact, Exploitability, and Mitigation Steps | Wiz

💬Community

1
Bugzilla
CVE-2026-31789 openssl: OpenSSL: Heap buffer overflow on 32-bit systems from large X.509 certificate processing2026-03-25
CVE-2026-31789 — Out-of-bounds Write in Openssl | cvebase