High 7.4Published Oct 22, 2026

CVE-2026-114616Authlib accepts an empty HMAC key, allowing JWS/JWT signature forgery (HS256/HS384/HS512)

Updated under an hour ago (Oct 28, 2026, 3:10 PM ET)

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It affects authlib. Add what you run to find out whether that includes you.

EPSS puts the chance of exploitation in the next 30 days at 0.21%, higher than 11% of scored CVEs.

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Every CVE for authlib

Exploited in the last 30 days

Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to 1.9.1, Authlib's OctKey.import_key() and HMAC signing and verification path accept zero-length key material. If an application's secret lookup can return an empty string or empty bytes, a remote attacker can compute the deterministic HS256, HS384, or HS512 signature for arbitrary token claims and have Authlib treat the token as authentic. This issue is fixed in version 1.9.1.

CVSS: 7.4 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Weakness (CWE): CWE-287, CWE-326, CWE-1391
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): 0.21% (percentile 11)
Assigned by: GitHub_M
NVD analysis: Awaiting Analysis
Record last updated: Oct 22, 2026
First seen by InfoSec Signals: Oct 22, 2026

Affected products

Affected products

authlib authlib authlib:authlib (from the name)	before 1.9.1	CNA record

References

References

https://github.com/authlib/authlib/security/advisories/GHSA-8m4g-j4wp-wgcg	x-refsource-confirm
https://github.com/authlib/authlib/commit/4ff30db442c70e29486e1982cb0ad37c037f5f4b	x-refsource-misc
https://github.com/authlib/authlib/releases/tag/v1.9.1	x-refsource-misc

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.