Access of Resource Using Incompatible Type ('Type Confusion') Affecting wasmcloud package, versions <2.0.1-r0


Severity

Recommended
0.0
high
0
10

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Threat Intelligence

EPSS
0.04% (12th percentile)

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  • Snyk IDSNYK-CHAINGUARDLATEST-WASMCLOUD-15855877
  • published31 Mar 2026
  • disclosed4 Feb 2026

Introduced: 4 Feb 2026

CVE-2026-25537  (opens in a new tab)
CWE-843  (opens in a new tab)

How to fix?

Upgrade Chainguard wasmcloud to version 2.0.1-r0 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream wasmcloud package and not the wasmcloud package as distributed by Chainguard. See How to fix? for Chainguard relevant fixed versions and status.

jsonwebtoken is a JWT lib in rust. Prior to version 10.3.0, there is a Type Confusion vulnerability in jsonwebtoken, specifically, in its claim validation logic. When a standard claim (such as nbf or exp) is provided with an incorrect JSON type (Like a String instead of a Number), the library’s internal parsing mechanism marks the claim as “FailedToParse”. Crucially, the validation logic treats this “FailedToParse” state identically to “NotPresent”. This means that if a check is enabled (like: validate_nbf = true), but the claim is not explicitly marked as required in required_spec_claims, the library will skip the validation check entirely for the malformed claim, treating it as if it were not there. This allows attackers to bypass critical time-based security restrictions (like “Not Before” checks) and commit potential authentication and authorization bypasses. This issue has been patched in version 10.3.0.

CVSS Base Scores

version 3.1