auditing-jwt-verification-trust SKILL.md skillA
auditing-jwt-verification-trust from unboundcompute/security-agent-skills is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add unboundcompute/security-agent-skills/auditing-jwt-verification-trust@git:20260825.70f8609Pins git:20260825.70f8609 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- unboundcompute/security-agent-skills
- Path
skills/auditing-jwt-verification-trust/SKILL.md- Versions recorded
- 1
- Latest version
- git:20260825.70f8609, committed Aug 25, 2026
- Size
- 9,967 bytes
- Repository stars
- 26
- License
- MIT
Audit code that verifies a JSON Web Token for a signature or claims check that trusts token-supplied parameters, so an attacker can forge a token the server accepts, after the algorithm pinning and the key source are resolved. Covers an algorithm taken from the token header rather than pinned server-side, an RS256-to-HS256 key confusion where a public key is used as an HMAC secret, an accepted none algorithm or a verification call with signature checking off, a kid, jku, or x5u parameter…
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# Auditing JWT verification trust: when a signed token is verified on the token's own terms A JSON Web Token is only as trustworthy as the verification code, and the bug is verification that trusts what the token itself supplies: the algorithm from the header, the key from a header-named location. If the server accepts the token's `alg`, an attacker switches a signature-verified token to an HMAC one signed with the public key, or to `none`; if it fetches the key from the token's `kid`, `jku`, or `x5u`, the attacker points it at a key they control. You audit it by resolving whether the algorithm is pinned server-side and where the verification key comes from, then checking the claims. This is a source-code audit: the whole value is deciding whether a reported token flaw is actually reachable in this codebase, so the false-positive killers carry the weight. Token-generation entropy belongs to the randomness skill; the OAuth grant dance belongs to the OIDC skill. ## When to use - You are reviewing the code path that verifies a signed token and uses its claims for an identity decision. …
Read the whole file at its exact version.
How to install
mdr add unboundcompute/security-agent-skills/auditing-jwt-verification-trust@sha256:88e20dd1797f10b2The line at the top of this page pins the label git:20260825.70f8609, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_fshrlz5rk6rsenso)
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Versions
The registry has recorded 1 version of this file, committed on Aug 25, 2026.
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (9967 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
unboundcompute/security-agent-skills · 26 stars · license MIT · pushed 2026-09-08 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_fshrlz5rk6rsenso GET https://markdownregistry.com/api/v1/resolve?ref=unboundcompute/security-agent-skills/auditing-jwt-verification-trust GET https://markdownregistry.com/api/v1/blob/88e20dd1797f10b208620bd7a75e5886894f907ce64737acfa293061abd4527b
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.