CVE-2026-118374
LibreSSL ocspcheck through 4.4.0 Memory Exhaustion via Unbounded OCSP HTTP Response
LibreSSL ocspcheck through 4.4.0 contains a memory exhaustion vulnerability that allows malicious OCSP responders to exhaust memory by sending unbounded HTTP responses. Attackers controlling the responder or intercepting plain HTTP AIA OCSP traffic can stream endless headers or body data to http_head_read() and http_body_read(), denying certificate status checks.
Fixes and workarounds
Fix
The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.
Source: CNA: VulnCheckFix
The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.
Source: CNA: VulnCheckAffected products and versions
| Product | Versions | Authority |
|---|---|---|
| LibreSSL OpenBSD libressl/portable
github |
≥ 0; ≤ 4.4.0 (affected, semver)
Other versions: unaffected |
CNA: VulnCheck |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 4.0 / 8.2 high |
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N | CNA: VulnCheck |
| 3.1 / 5.9 medium |
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H | CNA: VulnCheck |
Exploit evidence
No exploit evidence in collected sources. This is not proof of no exploitation.
References
- https://github.com/openbsd/src/commit/bf5da63f53179ef423d18c56d6da89eaefb56228CNA: VulnCheck · patch
- https://github.com/openbsd/src/commit/de4274c56c9ace88232591d4c919d79281a8de59CNA: VulnCheck · patch
- https://github.com/openbsd/src/blob/f6f428241d469cf434e60b73fc834d0448f068d5/usr.sbin/ocspcheck/http.c#L419CNA: VulnCheck · technical-description
- https://ftp.openbsd.org/pub/OpenBSD/LibreSSL/libressl-4.4.0-relnotes.txtCNA: VulnCheck · release-notes
- https://github.com/libressl/portableCNA: VulnCheck · product
- https://www.vulncheck.com/advisories/libressl-ocspcheck-through-4.4.0-memory-exhaustion-via-unbounded-ocsp-http-responseCNA: VulnCheck · third-party-advisory
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