CVE-2026-85394

criticalpriority · track · 36OT risk · elevatedEPSS 0.002 · 13 %ileUS
grimoire priorityP2 · Scheduled
Exploitable?
—
no known exploitation
Likely / severe?
0.22% (13th) EPSS
CVSS 9.1 · critical
Is it mine?
2 products
Check your exposure
Who says so?
1 sources
osv

EPSS · scored 2026-10-27

python-jose through 3.5.0 fails to properly validate asymmetric keys in HMAC initialization, accepting DER-encoded public keys that lack PEM armor or SSH prefixes. Attackers holding the service's public key can forge HS256 tokens that pass verification when algorithms are not explicitly restricted. This is an incomplete fix for CVE-2024-33663.

01

cvss

Technical severity, 0–10. One row per scoring source.

9.3
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–critical · 6.5–9.3

v3.19.1criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Nprimary · disclosure@vulncheck.comexploitability 3.9 · impact 5.2
v3.16.5mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:Nsecondary · OSV
v4.09.3criticalCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/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:Xsecondary · disclosure@vulncheck.com
v4.08highCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/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:Xsecondary · CVSS-BT (t0sche)
02

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: no · Technical Impact: totalcoordinatorcisa_ssvcUS
03

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-327USCWE-347USCWE-347US
04

affected products (2)

Products and version ranges known to be affected.

05

advisories (5)

Vendor and ecosystem advisories describing this.

  • GHSA-3qf3-8w2g-rqmxpython-jose algorithm confusion guard bypassed by DER-encoded public keys2026-09-03ghsa · osvUS

    python-jose through 3.5.0 fails to properly validate asymmetric keys in HMAC initialization, accepting DER-encoded public keys that lack PEM armor or SSH prefixes. Attackers holding the service's public key can forge HS256 tokens that pass verification when algorithms are not explicitly restricted. This is an incomplete fix for CVE-2024-33663.

  • GHSA-6c5p-j8vq-pqhjpython-jose algorithm confusion with OpenSSH ECDSA keys2024-04-26ghsa · osvUS

    python-jose through 3.3.0 has algorithm confusion with OpenSSH ECDSA keys and other key formats. This is similar to CVE-2022-29217.

  • CVE-2024-336632024-04-25vendor · osvUS

    python-jose through 3.3.0 has algorithm confusion with OpenSSH ECDSA keys and other key formats. This is similar to CVE-2022-29217.

  • PYSEC-2024-2322024-04-26vendor · osvUS

    python-jose through 3.3.0 has algorithm confusion with OpenSSH ECDSA keys and other key formats. This is similar to CVE-2022-29217.

  • PYSEC-2026-4298python-jose algorithm confusion guard bypassed by DER-encoded public keys2026-10-15vendor · osvUS

    python-jose through 3.5.0 fails to properly validate asymmetric keys in HMAC initialization, accepting DER-encoded public keys that lack PEM armor or SSH prefixes. Attackers holding the service's public key can forge HS256 tokens that pass verification when algorithms are not explicitly restricted. This is an incomplete fix for CVE-2024-33663.

06

also known as (4)

Other names and identifiers for this entity.

07

sources

Which sources assert this record, and when.

osvNVDCVE.orgMITRE
published 2026-09-03modified 2026-09-03
08

references (6) nvd

External citations — patches, advisories, analysis.

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