CVE-2026-81721

HIGHPre-NVD 7.57.5
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to the CVSS score beside it.

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-08-27. The CNA's CVSS baseline 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: the CNA's CVSS, EPSS, GitHub Security Advisory
Trending — 3 sources updated this week
7.5EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.6%CVSS: 7.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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
7.5HIGHmedium confidence
EG Risk
49
EG Risk 49/100

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 (value × EchelonGraph’s weight)
Severity75% × 45%
The EG Score, 7.5 of 10.
Exploitation0.6% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
0.6%
EPSS %ILE
46th
KEV
Not listed

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Attend at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; 60 days if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

August 27, 2026

Last Modified

October 1, 2026

Advisory Details (2)

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

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 advisoryMentions a patch (unverified)

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 rangeFix by version rangeDependents
openssl-encrypt0.2.2 ... 1.4.8 (53 versions)
  • every version up to 1.4.9: fixed in 1.4.9
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 20× in last 7d / 106× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 100 of 175 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 75 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  2. 2026-10-13 06:17 UTCEG score recompute
  3. 2026-10-13 06:16 UTCGHSA enrichmentGHSA-9pph-4h37-568j · GitHub severity HIGH · GitHub CVSS 7.5
  4. 2026-10-12 16:35 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  5. 2026-10-12 14:56 UTCEG score recompute
  6. 2026-10-11 19:20 UTCEG score recompute
  7. 2026-10-11 16:36 UTCEG score recompute
  8. 2026-10-11 13:54 UTCEG score recompute
  9. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  10. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  11. 2026-10-10 14:06 UTCGHSA enrichmentGHSA-9pph-4h37-568j · GitHub severity HIGH · GitHub CVSS 7.5
  12. 2026-10-10 01:54 UTCEG score recompute
  13. 2026-10-10 01:54 UTCGHSA enrichmentGHSA-9pph-4h37-568j · GitHub severity HIGH · GitHub CVSS 7.5
  14. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  15. 2026-10-09 03:05 UTCEG score recompute
  16. 2026-10-09 03:05 UTCGHSA enrichmentGHSA-9pph-4h37-568j · GitHub severity HIGH · GitHub CVSS 7.5
  17. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  18. 2026-10-08 01:19 UTCEG score recompute
  19. 2026-10-08 01:19 UTCGHSA enrichmentGHSA-9pph-4h37-568j · GitHub severity HIGH · GitHub CVSS 7.5
  20. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  21. 2026-10-07 07:57 UTCGHSA enrichmentGHSA-9pph-4h37-568j · GitHub severity HIGH · GitHub CVSS 7.5
  22. 2026-10-06 19:44 UTCEG score recompute
  23. 2026-10-06 19:44 UTCGHSA enrichmentGHSA-9pph-4h37-568j · GitHub severity HIGH · GitHub CVSS 7.5
  24. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  25. 2026-10-06 07:33 UTCEG score recompute
Show 75 more
  1. 2026-10-06 07:32 UTCGHSA enrichmentGHSA-9pph-4h37-568j · GitHub severity HIGH · GitHub CVSS 7.5
  2. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  3. 2026-10-05 17:12 UTCGHSA enrichmentGHSA-9pph-4h37-568j · GitHub severity HIGH · GitHub CVSS 7.5
  4. 2026-10-05 05:00 UTCEG score recompute
  5. 2026-10-05 05:00 UTCGHSA enrichmentGHSA-9pph-4h37-568j · GitHub severity HIGH · GitHub CVSS 7.5
  6. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  7. 2026-10-04 16:47 UTCGHSA enrichmentGHSA-9pph-4h37-568j · GitHub severity HIGH · GitHub CVSS 7.5
  8. 2026-10-04 04:33 UTCGHSA enrichmentGHSA-9pph-4h37-568j · GitHub severity HIGH · GitHub CVSS 7.5
  9. 2026-10-03 16:19 UTCEG score recompute
  10. 2026-10-03 16:19 UTCGHSA enrichmentGHSA-9pph-4h37-568j · GitHub severity HIGH · GitHub CVSS 7.5
  11. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  12. 2026-10-03 04:07 UTCEG score recompute
  13. 2026-10-03 04:07 UTCGHSA enrichmentGHSA-9pph-4h37-568j · GitHub severity HIGH · GitHub CVSS 7.5
  14. 2026-10-02 17:57 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  15. 2026-10-02 15:51 UTCGHSA enrichmentGHSA-9pph-4h37-568j · GitHub severity HIGH · GitHub CVSS 7.5
  16. 2026-10-02 03:39 UTCEG score recompute
  17. 2026-10-02 03:39 UTCGHSA enrichmentGHSA-9pph-4h37-568j · GitHub severity HIGH · GitHub CVSS 7.5
  18. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  19. 2026-10-01 15:27 UTCEG score recompute
  20. 2026-10-01 15:27 UTCGHSA enrichmentGHSA-9pph-4h37-568j · GitHub severity HIGH · GitHub CVSS 7.5
  21. 2026-10-01 08:06 UTCGHSA enrichmentGHSA-9pph-4h37-568j · GitHub severity HIGH · GitHub CVSS 7.5
  22. 2026-09-30 19:54 UTCEG score recompute
  23. 2026-09-30 19:54 UTCGHSA enrichmentGHSA-9pph-4h37-568j · GitHub severity HIGH · GitHub CVSS 7.5
  24. 2026-09-30 15:04 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  25. 2026-09-30 05:00 UTCEG score recompute
  26. 2026-09-30 05:00 UTCGHSA enrichmentGHSA-9pph-4h37-568j · GitHub severity HIGH · GitHub CVSS 7.5
  27. 2026-09-29 12:16 UTCEG score recompute
  28. 2026-09-29 12:16 UTCGHSA enrichmentGHSA-9pph-4h37-568j · GitHub severity HIGH · GitHub CVSS 7.5
  29. 2026-09-28 21:15 UTCEG score recompute
  30. 2026-09-28 21:15 UTCGHSA enrichmentGHSA-9pph-4h37-568j · GitHub severity HIGH · GitHub CVSS 7.5
  31. 2026-09-28 13:52 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  32. 2026-09-28 07:19 UTCGHSA enrichmentGHSA-9pph-4h37-568j · GitHub severity HIGH · GitHub CVSS 7.5
  33. 2026-09-27 19:07 UTCEG score recompute
  34. 2026-09-27 19:07 UTCGHSA enrichmentGHSA-9pph-4h37-568j · GitHub severity HIGH · GitHub CVSS 7.5
  35. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  36. 2026-09-27 06:55 UTCGHSA enrichmentGHSA-9pph-4h37-568j · GitHub severity HIGH · GitHub CVSS 7.5
  37. 2026-09-26 18:43 UTCEG score recompute
  38. 2026-09-26 18:43 UTCGHSA enrichmentGHSA-9pph-4h37-568j · GitHub severity HIGH · GitHub CVSS 7.5
  39. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  40. 2026-09-25 08:31 UTCGHSA enrichmentGHSA-9pph-4h37-568j · GitHub severity HIGH · GitHub CVSS 7.5
  41. 2026-09-24 20:19 UTCEG score recompute
  42. 2026-09-24 20:19 UTCGHSA enrichmentGHSA-9pph-4h37-568j · GitHub severity HIGH · GitHub CVSS 7.5
  43. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  44. 2026-09-24 08:05 UTCGHSA enrichmentGHSA-9pph-4h37-568j · GitHub severity HIGH · GitHub CVSS 7.5
  45. 2026-09-23 19:54 UTCEG score recompute
  46. 2026-09-23 19:54 UTCGHSA enrichmentGHSA-9pph-4h37-568j · GitHub severity HIGH · GitHub CVSS 7.5
  47. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  48. 2026-09-23 06:56 UTCGHSA enrichmentGHSA-9pph-4h37-568j · GitHub severity HIGH · GitHub CVSS 7.5
  49. 2026-09-22 18:44 UTCEG score recompute
  50. 2026-09-22 18:44 UTCGHSA enrichmentGHSA-9pph-4h37-568j · GitHub severity HIGH · GitHub CVSS 7.5
  51. 2026-09-22 16:01 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  52. 2026-09-22 06:20 UTCEG score recompute
  53. 2026-09-22 06:20 UTCGHSA enrichmentGHSA-9pph-4h37-568j · GitHub severity HIGH · GitHub CVSS 7.5
  54. 2026-09-21 21:09 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  55. 2026-09-21 18:07 UTCGHSA enrichmentGHSA-9pph-4h37-568j · GitHub severity HIGH · GitHub CVSS 7.5
  56. 2026-09-21 05:55 UTCEG score recompute
  57. 2026-09-21 05:55 UTCGHSA enrichmentGHSA-9pph-4h37-568j · GitHub severity HIGH · GitHub CVSS 7.5
  58. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  59. 2026-09-20 17:43 UTCGHSA enrichmentGHSA-9pph-4h37-568j · GitHub severity HIGH · GitHub CVSS 7.5
  60. 2026-09-20 05:15 UTCGHSA enrichmentGHSA-9pph-4h37-568j · GitHub severity HIGH · GitHub CVSS 7.5
  61. 2026-09-19 17:03 UTCEG score recompute
  62. 2026-09-19 17:03 UTCGHSA enrichmentGHSA-9pph-4h37-568j · GitHub severity HIGH · GitHub CVSS 7.5
  63. 2026-09-19 04:49 UTCEG score recompute
  64. 2026-09-19 04:48 UTCGHSA enrichmentGHSA-9pph-4h37-568j · GitHub severity HIGH · GitHub CVSS 7.5
  65. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  66. 2026-09-18 16:34 UTCGHSA enrichmentGHSA-9pph-4h37-568j · GitHub severity HIGH · GitHub CVSS 7.5
  67. 2026-09-18 04:22 UTCEG score recompute
  68. 2026-09-18 04:22 UTCGHSA enrichmentGHSA-9pph-4h37-568j · GitHub severity HIGH · GitHub CVSS 7.5
  69. 2026-09-17 16:10 UTCGHSA enrichmentGHSA-9pph-4h37-568j · GitHub severity HIGH · GitHub CVSS 7.5
  70. 2026-09-17 03:58 UTCGHSA enrichmentGHSA-9pph-4h37-568j · GitHub severity HIGH · GitHub CVSS 7.5
  71. 2026-09-16 15:46 UTCEG score recompute
  72. 2026-09-16 15:46 UTCGHSA enrichmentGHSA-9pph-4h37-568j · GitHub severity HIGH · GitHub CVSS 7.5
  73. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  74. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  75. 2026-09-16 03:33 UTCGHSA enrichmentGHSA-9pph-4h37-568j · GitHub severity HIGH · GitHub CVSS 7.5

Related CVEs(same product + same CWE)

Frequently asked(5)

What is CVE-2026-81721?
CVE-2026-81721 is a high-severity vulnerability; its CVE record was 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 made public?
CVE-2026-81721 was made public on August 12, 2026: that is the date its CVE record's CNA, VulnCheck, gives for when the vulnerability was made public. The CVE record itself was published on August 27, 2026. EchelonGraph's copy of the record carries a last-modified date of October 1, 2026; the record at its source may have been updated since.
Is CVE-2026-81721 actively exploited?
CVE-2026-81721 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.6% probability of exploitation in the next 30 days (46th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-81721?
CVE-2026-81721 has a CVSS base score of 7.5 (the CNA's own assessment, by vulncheck; NVD's own analysis pending).
How do I remediate CVE-2026-81721?
A fix for CVE-2026-81721 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-81721 are linked in the Vendor Advisories panel on this page.

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