Vulnerability · Published May 13, 2026 · Assigned by GitHub_M

CVE-2026-44459Hono: Improper validation of NumericDate claims (exp, nbf, iat) in JWT verify()

Low 3.8

In plain English

A low-severity security flaw in hono from honojs. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 12% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)3.8Low

Exploit odds (30 days)0.2%top 87.9% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.18, improper validation of the JWT NumericDate claims exp, nbf, and iat in hono/utils/jwt allows tokens with non-spec-compliant claim values to silently bypass time-based checks. This issue is not exploitable by an anonymous attacker; it only manifests when a malformed claim value reaches verify() — typically when the application itself issues such tokens, or when the signing key is otherwise under attacker control. This vulnerability is fixed in 4.12.18.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
npm	hono	4.12.18	GHSA-hm8q-7f3q-5f36

Affected products (as reported)

Vendor	Product	Versions
honojs	hono	< 4.12.18

Weakness: CWE-1284 · Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:N

References

https://github.com/honojs/hono/security/advisories/GHSA-hm8q-7f3q-5f36 x_refsource_CONFIRM