Reference page — cumulative record through Thursday, October 8, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.
AV AC PR UI S C I A CVSS EPSS %ile KEV N L L N U N L N 4.3 .0013 2.2 —
AFFECTED Product Versions Fixed Mattermost 11.9.0 – 11.10.0
TIMELINE Jun 1 Reserved by Mattermost Sep 14 Published (CNA: Mattermost) Oct 7 RESCORED — CVE-2026-10542 (Mattermost). CVSS 5 → 4.3 (NVD).
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to validate channel action ownership which allows channel managers to update actions in other channels via the channel action update endpoint.. Mattermost Advisory ID: MMSA-2026-00692
| Date | Event | Detail |
|---|---|---|
| June 1, 2026 | Reserved | Reserved by Mattermost |
| September 14, 2026 | Published | Published (CNA: Mattermost) |
| October 7, 2026 | RESCORED | RESCORED — CVE-2026-10542 (Mattermost). CVSS 5 → 4.3 (NVD). |
| Vendor | Product / Package | Ecosystem | Version introduced | Fixed |
|---|---|---|---|---|
| Mattermost | Mattermost | — | 11.9.0 | 11.10.0 |
Authoritative record: CVE-2026-10542 at cve.org
Vendors: mattermost
Weaknesses: CWE-639
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-10542 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Thursday, October 8, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.
