CVE-2026-81721 json
openssl_encrypt before 1.4.9 Denial of Service via KDF
published 2mo ago modified last mo. also EUVD-2026-67071 , GHSA-7894-5gw8-69hr , PYSEC-2026-3803
- cvss
- 7.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.6%
- EPSS 0.6% chance of exploitation in 30 days, percentile 48%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- pypi openssl-encrypt 1.4.9
- jahlives openssl_encrypt 1.4.9
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Check with FencerCISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 2mo ago
Exploit prediction
0.58% chance of exploitation in the next 30 days, higher than 48% of all scored CVEs (FIRST EPSS, 2026-11-11).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 8.7 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N |
| CNA | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| CNA | 4.0 | 8.7 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| pypi | openssl-encrypt | <1.4.9 |
1.4.9 |
Affected products
- jahlives openssl_encrypt
Classification
- Weakness
-
- CWE-400 Uncontrolled Resource Consumption
References
-
github.com
/jahlives/openssl_encrypt/security/advisories/GHSA-7894-5gw8-69hr
vendor-advisory, advisory
-
vulncheck.com
/advisories/openssl-encrypt-before-1.4.9-denial-of-service-via-kdf-2
third-party-advisory, advisory
Sources
- CVE List CVE-2026-81721
- NVD CVE-2026-81721
- OSV PYSEC-2026-3803
- Maintainer advisory GHSA-7894-5gw8-69hr
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
The maintainers of jahlives/openssl_encrypt published their own advisory on GitHub. Reviewed sources take precedence over it.