CVE-2026-63074

MEDIUMPre-NVD 5.95.9—
EchelonGraph scoreHIGH confidence

Score 5.9 from GitHub Security Advisory published 2026-08-25. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 5.9; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, ghsa
Trending — 6 sources updated this week
5.9EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.9Exploit: None knownExposed: 0

A fix is available — apply 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 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.

CVSS v3
5.9
EG Score
5.9(high)
EG Risk
27(Track)
EG Risk 27/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity59% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
40%
KEV
Not listed

Published

August 25, 2026

Last Modified

August 25, 2026

Advisory Details (6)

Auto-updated Aug 25, 2026
Upstream fix merged — awaiting tagged release. Sources: github_commit.
github_commit

commit 21a5d9658b0c (openssl/openssl)

Fix landed in openssl/openssl commit 21a5d9658b0c — awaiting tagged release

https://github.com/openssl/openssl/commit/21a5d9658b0c66daace60e10ea18ff32a448de9f
github_commit

commit f636f9ca0fa1 (openssl/openssl)

Fix landed in openssl/openssl commit f636f9ca0fa1 — awaiting tagged release

https://github.com/openssl/openssl/commit/f636f9ca0fa1bae5b42f9e787f025c96fb09c43a
github_commit

commit 75360af9650d (openssl/openssl)

Fix landed in openssl/openssl commit 75360af9650d — awaiting tagged release

https://github.com/openssl/openssl/commit/75360af9650d4e0c82ba0050c5c9912cd79e54af
github_commit

commit 01e567978a55 (openssl/openssl)

Fix landed in openssl/openssl commit 01e567978a55 — awaiting tagged release

https://github.com/openssl/openssl/commit/01e567978a55fba18142a230380c31296049fae7
github_commit

commit 74ae7f6df47a (openssl/openssl)

Fix landed in openssl/openssl commit 74ae7f6df47a — awaiting tagged release

https://github.com/openssl/openssl/commit/74ae7f6df47a5767c1010b88c47507dfc5b32c46
generic
https://openssl-library.org/news/secadv/20260825.txt

Vendor Advisories for CVE-2026-63074(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntuopenssl-provider-legacy (3.5.5-1ubuntu3.4) @ resolute2026-08-26ubuntu

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

All Vendor Advisories

(1)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 9× in last 7d / 9× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-08-26 14:46 UTCEPSS rescore
  2. 2026-08-26 13:03 UTCEG score recompute
  3. 2026-08-26 13:03 UTCVendor advisory
  4. 2026-08-26 13:03 UTCGHSA enrichment
  5. 2026-08-25 14:55 UTCEG score recompute▲ 5.90
  6. 2026-08-25 14:54 UTCMITRE cvelistV5CVSS v3 → 5.9 · severity → MEDIUM
  7. 2026-08-25 13:21 UTCNVD update
  8. 2026-08-25 13:16 UTCEG score recompute
  9. 2026-08-25 13:15 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-63074?
CVE-2026-63074 is a medium vulnerability published on August 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 OSSLCMPCTX frequently, this cache of extraCerts may grow unboundedly, and a malicious…
When was CVE-2026-63074 disclosed?
CVE-2026-63074 was first published in the National Vulnerability Database on August 25, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-63074 actively exploited?
CVE-2026-63074 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 60.1% of all scored CVEs.
What is the CVSS score of CVE-2026-63074?
CVE-2026-63074 has a CVSS v3.1 base score of 5.9 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-63074?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-63074, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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