CVE-2025-66622
matrix-sdk-base is vulnerable to DoS via custom m.room.join_rules event values
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
Description
matrix-sdk-base is the base component to build a Matrix client library. Versions 0.14.1 and prior are unable to handle responses that include custom m.room.join_rules values due to a serialization bug. This can be exploited to cause a denial-of-service condition, if a user is invited to a room with non-standard join rules, the crate's sync process will stall, preventing further processing for all rooms. This is fixed in version 0.16.0.
Timeline
ID reserved
By GitHub_M
- 4 days later
· 4 days later
Published
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 4.0 | Low1.3 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U |
| NVDNVD · Analyzed | 4.0 | Low1.3 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
- EPSS (exploitation in 30 days)
- 0.41% · top 64% of all CVEs (7 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Low 1.3.
Weakness
Affected products
- affected < 0.16.0
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- crates.iomatrix-sdk-baseGHSA-jj6p-3m75-g2p3 (opens in a new tab)
References (4)
- https://github.com/matrix-org/matrix-rust-sdk/security/advisories/GHSA-jj6p-3m75-g2p3 (opens in a new tab)x_refsource_CONFIRM
- https://github.com/matrix-org/matrix-rust-sdk/pull/5924 (opens in a new tab)x_refsource_MISC
- https://github.com/matrix-org/matrix-rust-sdk/commit/4ea0418abefab2aa93f8851a4d39c723e703e6b0 (opens in a new tab)x_refsource_MISC
- https://rustsec.org/advisories/RUSTSEC-2025-0135.html (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-jj6p-3m75-g2p3 (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2025-66622)Record last updated .