CVE-2026-81688

HIGHPre-NVD 7.57.5—
EchelonGraph scoreHIGH confidence

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-08-27. a secondary CVSS source baseline 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this week
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.5Exploit: 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 1.4.9 store an unkeyed SHA-256 hash of the plaintext in the cleartext file header metadata. Attackers can read this hash without the password to confirm guessed plaintexts offline or fingerprint identical plaintexts across separately-encrypted files.

CVSS v3
7.5
EG Score
7.5(high)
EG Risk
49(Track)
EG Risk 49/100SSVC: 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
Severity75% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
10%
KEV
Not listed

Published

August 27, 2026

Last Modified

August 28, 2026

Advisory Details (2)

Auto-updated Aug 27, 2026
Patch available. Sources: github.
generic

openssl_encrypt before 1.4.9 Plaintext Confirmation Oracle via SHA-256 | Advisories | VulnCheck

https://www.vulncheck.com/advisories/openssl-encrypt-before-1.4.9-plaintext-confirmation-oracle-via-sha-256
github Patch Available

Unkeyed SHA-256 of the plaintext stored in the cleartext file header is a plaintext-confirmation oracle · Advisory · jahlives/openssl_encrypt · GitHub

https://github.com/jahlives/openssl_encrypt/security/advisories/GHSA-7c3q-gp4v-q29q

Vendor Advisories for CVE-2026-81688(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 16× in last 7d / 16× 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. 2026-08-30 04:55 UTCEG score recompute
  2. 2026-08-30 04:54 UTCGHSA enrichment
  3. 2026-08-30 01:22 UTCEPSS rescore
  4. 2026-08-29 17:37 UTCGHSA enrichment
  5. 2026-08-29 06:20 UTCEG score recompute
  6. 2026-08-29 06:20 UTCGHSA enrichment
  7. 2026-08-28 21:42 UTCEPSS rescore
  8. 2026-08-28 19:03 UTCGHSA enrichment
  9. 2026-08-28 07:45 UTCGHSA enrichment
  10. 2026-08-27 20:27 UTCEG score recompute
  11. 2026-08-27 20:27 UTCGHSA enrichment
  12. 2026-08-27 20:18 UTCEG score recompute
  13. 2026-08-27 20:18 UTCGHSA enrichment
  14. 2026-08-27 17:25 UTCEG score recompute
  15. 2026-08-27 16:47 UTCEG score recompute
  16. 2026-08-27 16:43 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-81688?
CVE-2026-81688 is a high vulnerability published on August 27, 2026. openssl_encrypt versions before 1.4.9 store an unkeyed SHA-256 hash of the plaintext in the cleartext file header metadata. Attackers can read this hash without the password to confirm guessed plaintexts offline or fingerprint identical plaintexts across separately-encrypted files.
When was CVE-2026-81688 disclosed?
CVE-2026-81688 was first published in the National Vulnerability Database on August 27, 2026, with the most recent update on August 28, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-81688 actively exploited?
CVE-2026-81688 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 90.4% of all scored CVEs.
What is the CVSS score of CVE-2026-81688?
CVE-2026-81688 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-81688?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-81688, 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

Explore the affected products and dependency analysis for CVE-2026-81688

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