Out-of-bounds Read in Openssl
CVE-2026-34180
Issue summary: Parsing a crafted DER-encoded ASN.1 structure with a primitive element whose content exceeds 2 gigabytes in length may cause a heap buffer over-read on 64-bit Unix and Unix-like platforms. Impact summary: The heap buffer ov…
Vulnerability class: Buffer Overflow
EPSS: 0.010 (60.0th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Openssl — versions 4.0.0, 3.6.0, 3.5.0
Weakness classification (CWE)
References
- openssl-security@openssl.org
- openssl-security@openssl.org
- openssl-security@openssl.org
- openssl-security@openssl.org
- openssl-security@openssl.org
- openssl-security@openssl.org (vendor-advisory, Vendor Advisory)
- openssl-security@openssl.org (Patch, patch)
- openssl-security@openssl.org (Patch, patch)
- openssl-security@openssl.org (Patch, patch)
- openssl-security@openssl.org (Patch, patch)
Frequently asked questions
- What is CVE-2026-34180?
- CVE-2026-34180 is a high-severity vulnerability in Openssl, classified under Out-of-bounds Read. CVSS score: 7.5/10. Published 2026-06-09.
- How severe is CVE-2026-34180?
- High severity. CVSS v3 base score is 7.5 out of 10.