What is CVE-2026-22817?

CVE-2026-22817 is a high-severity vulnerability in Honojs Hono, classified under Improper Verification of Cryptographic Signature. CVSS score: 8.2/10. Published 2026-01-13.

How severe is CVE-2026-22817?

High severity. CVSS v3 base score is 8.2 out of 10.

Vulnerability in Honojs Hono

CVE-2026-22817

Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.11.4, there is a flaw in Hono’s JWK/JWKS JWT verification middleware allowed the JWT header’s alg value to influence signature verification wh…

EPSS: 0.000 (6.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N.

Affected products

Honojs Hono — versions < 4.11.4

Weakness classification (CWE)

CWE-347 — Improper Verification of Cryptographic Signature

References

https://github.com/honojs/hono/security/advisories/GHSA-f67f-6cw9-8mq4 (x_refsource_CONFIRM)
https://github.com/honojs/hono/commit/cc0aa7ae327ed84cc391d29086dec2a3e44e7a1f (x_refsource_MISC)

Frequently asked questions

What is CVE-2026-22817?: CVE-2026-22817 is a high-severity vulnerability in Honojs Hono, classified under Improper Verification of Cryptographic Signature. CVSS score: 8.2/10. Published 2026-01-13.
How severe is CVE-2026-22817?: High severity. CVSS v3 base score is 8.2 out of 10.