CVE-2026-74900

CRITICALPre-NVD 9.89.8—
EchelonGraph scoreHIGH confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-08-17. a secondary CVSS source baseline 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this week
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.8Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

openssl_encrypt versions before 1.4.0 contain a critical vulnerability in pqc.py where KEM decapsulation failures silently fall back to simulation mode, generating a deterministic shared secret from only 16 bytes of the private key and publicly available encapsulated key data. Attackers who obtain 16 bytes of the private key can compute the shared secret and decrypt all ciphertext, as the fallback triggers on any KEM failure without raising an error.

CVSS v3
9.8
EG Score
9.8(high)
EG Risk
59(Track)
EG Risk 59/100SSVC: 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
Severity98% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
27%
KEV
Not listed

Published

August 17, 2026

Last Modified

August 17, 2026

Advisory Details (2)

Auto-updated Aug 17, 2026
Patch available. Sources: github.
generic

openssl_encrypt before 1.4.0 Weak Shared Secret via PQC Simulation Mode | Advisories | VulnCheck

https://www.vulncheck.com/advisories/openssl-encrypt-before-weak-shared-secret-via-pqc-simulation-mode
github Patch Available

PQC simulation mode fallback uses weak deterministic shared secret · Advisory · jahlives/openssl_encrypt · GitHub

https://github.com/jahlives/openssl_encrypt/security/advisories/GHSA-p3gq-pcg9-qvfv

Vendor Advisories for CVE-2026-74900(1)

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

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 34× in last 7d / 34× 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. 2026-08-21 04:38 UTCGHSA enrichment
  2. 2026-08-21 00:20 UTCEG score recompute
  3. 2026-08-21 00:20 UTCGHSA enrichment
  4. 2026-08-20 22:56 UTCEPSS rescore
  5. 2026-08-20 20:03 UTCGHSA enrichment
  6. 2026-08-20 15:46 UTCGHSA enrichment
  7. 2026-08-20 11:26 UTCGHSA enrichment
  8. 2026-08-20 07:09 UTCGHSA enrichment
  9. 2026-08-20 02:52 UTCGHSA enrichment
  10. 2026-08-19 22:35 UTCGHSA enrichment
  11. 2026-08-19 18:18 UTCEG score recompute
  12. 2026-08-19 18:17 UTCGHSA enrichment
  13. 2026-08-19 17:04 UTCEPSS rescore
  14. 2026-08-19 13:04 UTCGHSA enrichment
  15. 2026-08-19 08:47 UTCGHSA enrichment
  16. 2026-08-19 04:28 UTCGHSA enrichment
  17. 2026-08-19 00:10 UTCGHSA enrichment
  18. 2026-08-18 19:52 UTCGHSA enrichment
  19. 2026-08-18 15:35 UTCEG score recompute
  20. 2026-08-18 15:35 UTCGHSA enrichment
  21. 2026-08-18 13:49 UTCEPSS rescore
  22. 2026-08-18 13:49 UTCEPSS rescore
  23. 2026-08-18 11:11 UTCGHSA enrichment
  24. 2026-08-18 06:52 UTCGHSA enrichment
  25. 2026-08-18 02:34 UTCGHSA enrichment
Show 9 more
  1. 2026-08-17 22:17 UTCGHSA enrichment
  2. 2026-08-17 17:59 UTCGHSA enrichment
  3. 2026-08-17 13:30 UTCEG score recompute
  4. 2026-08-17 13:30 UTCGHSA enrichment
  5. 2026-08-17 12:56 UTCEG score recompute
  6. 2026-08-17 12:56 UTCGHSA enrichment
  7. 2026-08-17 11:38 UTCEG score recompute
  8. 2026-08-17 11:13 UTCEG score recompute
  9. 2026-08-17 11:12 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-74900?
CVE-2026-74900 is a critical vulnerability published on August 17, 2026. openssl_encrypt versions before 1.4.0 contain a critical vulnerability in pqc.py where KEM decapsulation failures silently fall back to simulation mode, generating a deterministic shared secret from only 16 bytes of the private key and publicly available encapsulated key data. Attackers who obtain…
When was CVE-2026-74900 disclosed?
CVE-2026-74900 was first published in the National Vulnerability Database on August 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-74900 actively exploited?
CVE-2026-74900 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 73.2% of all scored CVEs.
What is the CVSS score of CVE-2026-74900?
CVE-2026-74900 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-74900?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-74900, 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.

Dependency Blast Radius

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