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22Track

CMP Indefinite Cache Growth of ExtraCerts

OpenSSL · CVE-2026-63074
0 news outlets0 CERTs and agencies0 researchers

Assessment: Track

SSVC decision points: exploitation none, automatable no, technical impact partial, deployment high.

What is it?

Issue summary: The OpenSSL Certificate Management Protocol (CMP) caches additional certificates (extraCerts) sent in a CMP message, but never expunges them (for instance if they are invalid). If a server reuses an OSSL_CMP_CTX frequently, this cache of extraCerts may grow unboundedly, and a malicious client may flood a CMP server with requests driving this growth. Impact summary: Users utilizing a CMP server that reuses a single OSSL_CMP_CTX for the lifetime of a server process may observe unbounded memory growth in the event a malicious client repeatedly sends requests containing unique extra certificates, which may lead to OOM conditions. CWE: CWE-770: Allocation of Resources Without Limits or Throttling Description: If a remote user sends CMP messages to a server with a list of extraCerts and the message is rejected, the extraCerts from the message remains in the server contexts untrusted certificate stack. This exposes servers with long lived ctx objects to Denial of Service attacks in which an attacker sends messages intending to be rejected with a large list of additional certificates repeatedly, forcing the server to store them indefinitely. The issue was fixed by r

Evidence

No coverage recorded yet.

Exploitation

  • Public proof of concept
  • Exploited in the wild
  • Listed as known exploited
CVSS
5.9
EPSS
0.6%
First seen
2 d ago
Status
corroborated

All OpenSSL vulnerabilities