5.9

CVE-2025-27936: mattermost Observable Timing Discrepancy

CVSS: 5.9v3.1MediumAnalyzed
AliasesGHSA-2j87-p623-8cc2GO-2025-3618CGA-h7x5-hghj-rc8c
Published 16-04-2025Last modified 16-04-2025
Open JSON

Vulnerability summary

CVE-2025-27936 is a medium (CVSS 5.9) Observable Timing Discrepancy vulnerability in mattermost. EPSS estimates a 0.34% chance of exploitation in the next 30 days, higher than 26.5% of scored vulnerabilities.

Overall risk
24/100
0100
Low · default modelHow is this calculated?
CVSS score
5.9/10
010
Medium · v3.1 (NVD)
EPSS score
0.34%
0%100%
Low · +0.01 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 1 · Related 2
OPENSUSE-SU-2025:15017-1CGA-WV5W-MG9X-7CR4

Timeline

  1. 16-04-2025
    PublishedVulnerability first disclosed.
  2. 16-04-2025
    Last modifiedVulnerability information updated.

Description

Mattermost Plugin MSTeams versions <2.1.0 and Mattermost Server versions 10.5.x <=10.5.1 with the MS Teams plugin enabled fail to perform constant time comparison on a MSTeams plugin webhook secret which allows an attacker to retrieve the webhook secret of the MSTeams plugin via a timing attack during webhook secret comparison.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.34%

Chance of exploitation in the next 30 days

Percentile

27%

Versus all other CVEs

30-day change

+0.01 pp

From 0.34% on 20-09-2026

20-09-202620-10-2026
EPSS score
0.34%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Mattermost3 products
Chainguard2 products
  • mattermost-fips-10.5All versions (No fix recorded)
  • mattermost-fips-10.5-compatAll versions (No fix recorded)
Github.com/mattermost2 products
  • mattermost-plugin-msteams< 2.1.0 | All versions (No fix recorded)
  • mattermost-server≥ 10.5.0+incompatible, < 10.5.2+incompatible
Github.com/mattermost/mattermost-server2 products
  • v5All versions (No fix recorded)
  • v6All versions (No fix recorded)
Github.com/mattermost/mattermost/server1 product
  • v8≥ 10.5.0, < 10.5.2 | < 8.0.0-20250314142426-c049748b8863 | < 8.0.0-20250218121836-2b5275d87136

5 vendors · 10 products

References

6 links