What is CVE-2026-22818?

CVE-2026-22818 is a high-severity vulnerability in Hono, classified under Improper Verification of Cryptographic Signature. CVSS score: 8.2/10. Published 2026-01-13.

How severe is CVE-2026-22818?

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

Vulnerability in Hono

CVE-2026-22818

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 algorithm specified in the JWT header to influence signature…

EPSS: 0.001 (2.0th 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

Hono
Honojs Hono — versions < 4.11.4

Weakness classification (CWE)

CWE-347 — Improper Verification of Cryptographic Signature

References

security-advisories@github.com (x_refsource_CONFIRM, Third Party Advisory)
security-advisories@github.com (Patch, x_refsource_MISC)

Frequently asked questions

What is CVE-2026-22818?: CVE-2026-22818 is a high-severity vulnerability in Hono, classified under Improper Verification of Cryptographic Signature. CVSS score: 8.2/10. Published 2026-01-13.
How severe is CVE-2026-22818?: High severity. CVSS v3 base score is 8.2 out of 10.