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.

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements Present

User Interaction None

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact None

Vulnerable System Availability Impact High

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity High

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
OpenBSD LibreSSL unaffected
Version Status Constraints
0 affected ≤ 4.4.0

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Project Subscriptions

Vendors Products
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Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://ftp.openbsd.org/pub/OpenBSD/LibreSSL/libressl-4.4.0-relnotes.txt cve-icon cve-icon
https://github.com/libressl/portable cve-icon cve-icon
https://github.com/openbsd/src/blob/f6f428241d469cf434e60b73fc834d0448f068d5/usr.sbin/ocspcheck/http.c#L419 cve-icon cve-icon
https://github.com/openbsd/src/commit/bf5da63f53179ef423d18c56d6da89eaefb56228 cve-icon cve-icon
https://github.com/openbsd/src/commit/de4274c56c9ace88232591d4c919d79281a8de59 cve-icon cve-icon
https://www.vulncheck.com/advisories/libressl-ocspcheck-through-4.4.0-memory-exhaustion-via-unbounded-ocsp-http-response cve-icon cve-icon
History

Wed, 28 Oct 2026 02:30:00 +0000

Type Values Removed Values Added
Description 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.
Title LibreSSL ocspcheck through 4.4.0 Memory Exhaustion via Unbounded OCSP HTTP Response
First Time appeared Openbsd
Openbsd libressl
Weaknesses CWE-770
CPEs cpe:2.3:a:openbsd:libressl:*:*:*:*:*:*:*:*
Vendors & Products Openbsd
Openbsd libressl
References
Metrics cvssV3_1

{'score': 5.9, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H'}

cvssV4_0

{'score': 8.2, 'vector': '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'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-10-28T02:03:22.183Z

Reserved: 2026-10-28T01:19:20.947Z

Link: CVE-2026-118374

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-28T03:17:13.923

Modified: 2026-10-28T03:17:13.923

Link: CVE-2026-118374

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-10-28T03:30:15Z

Weaknesses