Answer in brief
CVE-2026-63074 records a Medium severity (CVSS 5.9) vulnerability in CMP Indefinite Cache Growth of ExtraCerts. The current sources do not mark it as known exploited. The current feed maps OpenSSL/OpenSSL (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 5.9. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps OpenSSL/OpenSSL (generic). Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| OpenSSL/OpenSSLgeneric | >=4.0.0 <4.0.2 || >=3.6.0 <3.6.4 || >=3.5.0 <3.5.8 || >=3.4.0 <3.4.7 || >=3.0.0 <3.0.22 | 4.0.2, 3.6.4, 3.5.8, 3.4.7, 3.0.22 |
Published upstream
Aug 25, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 11, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 25, 2026
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 removing the added extra certs if the message is rejected, using the same method as when the context is configured to not do caching at all. FIPS impact: no As the CMP code lives outside the FIPS module boundary, no FIPS modules are affected by this CVE.
Quoted source text, attributed separately from HOL analysis.