CVE-2026-74890 json
openssl_encrypt before 1.4.0 HMAC Authentication Bypass via Environment Variable
published 9mo ago modified 18d ago also EUVD-2026-60109 , GHSA-rvc2-5jxq-gpcj , PYSEC-2026-3766
- cvss
- 5.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 11%
- public exploits
- 0
- none known
Summary
openssl_encrypt versions before 1.4.0 contain an authentication bypass vulnerability in CamelliaCipher that disables HMAC tag generation and verification when the PYTEST_CURRENT_TEST environment variable is set. Attackers with code execution can set this environment variable to produce unauthenticated ciphertext and bypass integrity protection on encrypted data.
Patch / fix
- pypi openssl-encrypt 1.4.0
- jahlives openssl_encrypt 1.4.0
Is CVE-2026-74890 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerCISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 2mo ago
Exploit prediction
0.21% chance of exploitation in the next 30 days, higher than 11% of all scored CVEs (FIRST EPSS, 2026-11-11).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 9.3 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N |
| CNA | 3.1 | 5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N |
| CNA | 4.0 | 9.3 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/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 | <1.4.0 |
1.4.0 |
Affected products
- jahlives openssl_encrypt
Classification
- Weakness
-
- CWE-345 Insufficient Verification of Data Authenticity
References
-
github.com
/jahlives/openssl_encrypt/security/advisories/GHSA-rvc2-5jxq-gpcj
vendor-advisory, mitigation, advisory
-
vulncheck.com
/advisories/openssl-encrypt-before-hmac-authentication-bypass-via-environment-variable
third-party-advisory, advisory
Sources
- CVE List CVE-2026-74890
- NVD CVE-2026-74890
- OSV PYSEC-2026-3766
- Maintainer advisory GHSA-rvc2-5jxq-gpcj
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.