CVE-2026-45057

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.

CVSS v3 4.9 MEDIUM

4.9^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 1.2 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required HIGH

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

References

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

Configurations

No configuration.

History

No history.

Information

Published : 2026-09-11 21:17

Updated : 2026-09-14 17:17

NVD link : CVE-2026-45057

Mitre link : CVE-2026-45057

CVE.ORG link : CVE-2026-45057

JSON object : View

Products Affected

No product.

CWE

CWE-345

Insufficient Verification of Data Authenticity

{"id": "CVE-2026-45057", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-45057", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-09-14T16:16:05.439558Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 4.9, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "HIGH", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 1.2}]}, "affected": [{"source": "security-advisories@github.com", "affectedData": [{"vendor": "matrix-org", "product": "matrix-sdk-ui", "versions": [{"status": "affected", "version": "< 0.16.1"}]}]}], "published": "2026-09-11T21:17:09.517", "references": [{"url": "https://github.com/matrix-org/matrix-rust-sdk/pull/6454", "source": "security-advisories@github.com"}, {"url": "https://github.com/matrix-org/matrix-rust-sdk/releases/tag/matrix-sdk-0.16.1", "source": "security-advisories@github.com"}, {"url": "https://github.com/matrix-org/matrix-rust-sdk/security/advisories/GHSA-h97m-27fx-42rx", "source": "security-advisories@github.com"}, {"url": "https://rustsec.org/advisories/RUSTSEC-2026-0158.html", "source": "security-advisories@github.com"}], "vulnStatus": "Received", "weaknesses": [{"type": "Secondary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-345"}]}], "descriptions": [{"lang": "en", "value": "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."}], "lastModified": "2026-09-14T17:17:44.573", "sourceIdentifier": "security-advisories@github.com"}