CVE-2026-45057

MEDIUM 4.9

matrix-sdk-ui: Incomplete edit validation

CVSS Score

4.9

EPSS Score

0.0%

EPSS Percentile

0th

matrix-sdk-ui provides GUI-centric utilities on top of matrix-rust-sdk. The message edit validation logic in the `matrix-sdk-ui` crate prior to 0.17.0 is missing a check: when replacing an encrypted event, the replacement event itself is not required to be encrypted. This enables a malicious homeserver administrators (or actors with equivalent power) to impersonate or spoof messages as if they were sent by a victim user. `matrix-sdk-ui` 0.17.0 fixes the message edit validation logic to align with the algorithm for replacement events[^1] described in the Matrix specification. No known workarounds are available.

CWE	CWE-345
Vendor	matrix-org
Product	matrix-sdk-ui
Published	Sep 11, 2026
Last Updated	Sep 14, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N

Attack Vector

Network

Attack Complexity

Low

Privileges Required

High

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

High

Availability

None

Affected Versions

matrix-org / matrix-sdk-ui

< 0.16.1

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/matrix-org/matrix-rust-sdk/security/advisories/GHSA-h97m-27fx-42rx github.com: https://github.com/matrix-org/matrix-rust-sdk/pull/6454 github.com: https://github.com/matrix-org/matrix-rust-sdk/releases/tag/matrix-sdk-0.16.1 rustsec.org: https://rustsec.org/advisories/RUSTSEC-2026-0158.html