5.9
MediumCVSS 3.1 · from VulnCheck
CVE-2026-118374
LibreSSL ocspcheck through 4.4.0 Memory Exhaustion via Unbounded OCSP HTTP Response
LibreSSL · Allocation without limits · CWE-770AffectedLibreSSL
FixA patch is linked in the references.
PublishedOct 28, 02:03 · VulnCheck
ScoredOct 28 · 5.9 · VulnCheck
Exploit code publicNone known · checked 21:18 UTC
ExploitedNone known · CISA KEV checked 22:09 UTC
What we know
No known exploitation. CISA KEV, checked 22:09 UTC.
No public exploit code known. Exploit-DB, Metasploit, Nuclei, checked 21:18 UTC.
An attacker only needs network access to the target. No login needed. CVSS: network, no privileges.
It only works under certain conditions, which makes it harder to pull off. CVSS: high attack complexity.
A successful attack can take the service down. CVSS impact.
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.
From VulnCheck
Affected and fixed versions
ProductAffectedFixed inLibreSSLup to 4.4.0–
Exploit code
Exploit-DBnone knownMetasploitnone knownNucleinone known