CVE-2026-81721

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 — 3 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 before 1.4.9 fails to validate KDF cost parameters in encrypted file metadata and keystore headers, allowing attackers to trigger unbounded memory allocation. Attackers can craft malicious encrypted files declaring arbitrarily large Argon2, scrypt, or balloon KDF parameters to exhaust system memory and crash the process without authentication.

CVSS v3
7.5
EG Score
7.5(high)
EG Risk
38(Track)
EG Risk 38/100SSVC: 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%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
33%
KEV
Not listed

Published

August 27, 2026

Last Modified

September 2, 2026

Advisory Details (2)

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

openssl_encrypt before 1.4.9 Denial of Service via KDF | Advisories | VulnCheck

https://www.vulncheck.com/advisories/openssl-encrypt-before-1.4.9-denial-of-service-via-kdf-2
github Patch Available

Pre-auth memory-exhaustion DoS via unbounded KDF cost parameters in encrypted-file metadata and keystore headers · Advisory · jahlives/openssl_encrypt · GitHub

https://github.com/jahlives/openssl_encrypt/security/advisories/GHSA-7894-5gw8-69hr

Vendor Advisories for CVE-2026-81721(1)

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

Affected Packages

(1 across 1 ecosystem)
PyPI(1)
PackageVulnerable rangeFixed inDependents
openssl-encrypt0.2.2 ... 1.4.8 (53 versions)1.4.9—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 25× in last 7d / 88× 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. 2026-09-19 04:49 UTCEG score recompute
  2. 2026-09-19 04:48 UTCGHSA enrichment
  3. 2026-09-18 19:28 UTCEPSS rescore
  4. 2026-09-18 16:34 UTCGHSA enrichment
  5. 2026-09-18 04:22 UTCEG score recompute
  6. 2026-09-18 04:22 UTCGHSA enrichment
  7. 2026-09-17 16:10 UTCGHSA enrichment
  8. 2026-09-17 03:58 UTCGHSA enrichment
  9. 2026-09-16 15:46 UTCEG score recompute
  10. 2026-09-16 15:46 UTCGHSA enrichment
  11. 2026-09-16 14:08 UTCEPSS rescore
  12. 2026-09-16 05:15 UTCEPSS rescore
  13. 2026-09-16 03:33 UTCGHSA enrichment
  14. 2026-09-15 15:21 UTCEG score recompute
  15. 2026-09-15 15:21 UTCGHSA enrichment
  16. 2026-09-15 03:12 UTCEPSS rescore
  17. 2026-09-15 03:12 UTCEPSS rescore
  18. 2026-09-15 03:08 UTCGHSA enrichment
  19. 2026-09-14 14:55 UTCGHSA enrichment
  20. 2026-09-14 02:43 UTCEG score recompute
  21. 2026-09-14 02:43 UTCGHSA enrichment
  22. 2026-09-13 14:30 UTCGHSA enrichment
  23. 2026-09-13 02:18 UTCEG score recompute
  24. 2026-09-13 02:18 UTCGHSA enrichment
  25. 2026-09-12 14:06 UTCGHSA enrichment
Show 63 more
  1. 2026-09-12 01:54 UTCEG score recompute
  2. 2026-09-12 01:54 UTCGHSA enrichment
  3. 2026-09-11 14:53 UTCEPSS rescore
  4. 2026-09-11 14:53 UTCEPSS rescore
  5. 2026-09-11 13:42 UTCEG score recompute
  6. 2026-09-11 13:42 UTCGHSA enrichment
  7. 2026-09-11 01:30 UTCGHSA enrichment
  8. 2026-09-10 13:18 UTCEG score recompute
  9. 2026-09-10 13:18 UTCGHSA enrichment
  10. 2026-09-10 01:06 UTCGHSA enrichment
  11. 2026-09-09 12:54 UTCGHSA enrichment
  12. 2026-09-09 00:40 UTCEG score recompute
  13. 2026-09-09 00:40 UTCGHSA enrichment
  14. 2026-09-08 22:01 UTCEPSS rescore
  15. 2026-09-08 04:01 UTCEG score recompute
  16. 2026-09-08 04:01 UTCGHSA enrichment
  17. 2026-09-07 15:48 UTCGHSA enrichment
  18. 2026-09-07 03:36 UTCGHSA enrichment
  19. 2026-09-06 15:20 UTCEG score recompute
  20. 2026-09-06 15:20 UTCGHSA enrichment
  21. 2026-09-06 13:48 UTCEPSS rescore
  22. 2026-09-06 03:07 UTCEG score recompute
  23. 2026-09-06 03:06 UTCGHSA enrichment
  24. 2026-09-05 15:31 UTCEPSS rescore
  25. 2026-09-05 14:54 UTCGHSA enrichment
  26. 2026-09-05 02:39 UTCGHSA enrichment
  27. 2026-09-04 14:26 UTCEG score recompute
  28. 2026-09-04 14:26 UTCGHSA enrichment
  29. 2026-09-04 05:07 UTCEPSS rescore
  30. 2026-09-04 02:11 UTCGHSA enrichment
  31. 2026-09-03 14:00 UTCGHSA enrichment
  32. 2026-09-03 01:48 UTCEG score recompute
  33. 2026-09-03 01:47 UTCGHSA enrichment
  34. 2026-09-02 14:12 UTCEPSS rescore
  35. 2026-09-02 13:35 UTCGHSA enrichment
  36. 2026-09-02 09:26 UTCGHSA enrichment
  37. 2026-09-01 21:13 UTCEG score recompute
  38. 2026-09-01 21:13 UTCGHSA enrichment
  39. 2026-09-01 13:54 UTCEPSS rescore
  40. 2026-09-01 09:02 UTCEG score recompute
  41. 2026-09-01 09:01 UTCGHSA enrichment
  42. 2026-09-01 04:40 UTCEPSS rescore
  43. 2026-09-01 04:40 UTCEPSS rescore
  44. 2026-08-31 20:48 UTCGHSA enrichment
  45. 2026-08-31 08:13 UTCGHSA enrichment
  46. 2026-08-30 19:56 UTCEG score recompute
  47. 2026-08-30 19:56 UTCGHSA enrichment
  48. 2026-08-30 19:18 UTCEPSS rescore
  49. 2026-08-30 19:17 UTCEPSS rescore
  50. 2026-08-30 07:44 UTCEG score recompute
  51. 2026-08-30 07:44 UTCGHSA enrichment
  52. 2026-08-30 01:22 UTCEPSS rescore
  53. 2026-08-29 19:32 UTCGHSA enrichment
  54. 2026-08-29 07:20 UTCEG score recompute
  55. 2026-08-29 07:20 UTCGHSA enrichment
  56. 2026-08-28 21:42 UTCEPSS rescore
  57. 2026-08-28 19:03 UTCGHSA enrichment
  58. 2026-08-28 08:41 UTCGHSA enrichment
  59. 2026-08-27 20:27 UTCEG score recompute
  60. 2026-08-27 20:27 UTCGHSA enrichment
  61. 2026-08-27 17:24 UTCEG score recompute
  62. 2026-08-27 16:47 UTCEG score recompute
  63. 2026-08-27 16:43 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-81721?
CVE-2026-81721 is a high vulnerability published on August 27, 2026. openssl_encrypt before 1.4.9 fails to validate KDF cost parameters in encrypted file metadata and keystore headers, allowing attackers to trigger unbounded memory allocation. Attackers can craft malicious encrypted files declaring arbitrarily large Argon2, scrypt, or balloon KDF parameters to…
When was CVE-2026-81721 disclosed?
CVE-2026-81721 was first published in the National Vulnerability Database on August 27, 2026, with the most recent update on September 2, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-81721 actively exploited?
CVE-2026-81721 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 66.7% of all scored CVEs.
What is the CVSS score of CVE-2026-81721?
CVE-2026-81721 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-81721?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-81721, 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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