JWT time-check bypass via malformed NumericDate claims
Published May 13, 2026 · Updated May 13, 2026
Improper NumericDate validation in Hono before 4.12.18 allows attackers to bypass JWT time checks with malformed signed tokens. The hono/utils/jwt verify() routine combines option, presence, and threshold tests in a short-circuiting expression, so falsy, non-finite, and nonnumeric claim values avoid rejection. Exploitation requires authority to issue a token accepted by the application, and the resulting token can be treated as unexpired or valid before its intended time.
Summary
What happened
Improper NumericDate validation in Hono before 4.12.18 allows attackers to bypass JWT time checks with malformed signed tokens. The hono/utils/jwt verify() routine combines option, presence, and threshold tests in a short-circuiting expression, so falsy, non-finite, and nonnumeric claim values avoid rejection. Exploitation requires authority to issue a token accepted by the application, and the resulting token can be treated as unexpired or valid before its intended time.
The record
- CVE
- CVE-2026-44459
- Published
- May 13, 2026
- Updated
- May 13, 2026
- Vendor
- Hono
- Product
- Hono
- Classifications
- CWE-1284, T1550.001
- Attack vector
- network
- Privileges
- Unavailable
Timeline
How it unfolded
- May 13, 2026CVE publishedPublication date reported by the CVE source.
- May 13, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=< 4.12.18
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
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Your stack
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