CVE-2025-54499Network attack vector

Secret recovery via non-constant-time comparisons

Published Oct 16, 2025 · Updated Oct 16, 2025

Timing side channel in Mattermost 10.5.0 through 10.5.10 and 10.11.0 through 10.11.2 allows remote authenticated users to recover secrets. Cloud API key and OAuth client-secret validation paths compare attacker-supplied values without constant-time handling, so response-time differences reveal matching bytes. A low-privileged remote account and repeated measurements are required; successful analysis discloses the compared secret without altering data or interrupting the service.

CVSS severity3.1
Low
EPSS probability0.27%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Timing side channel in Mattermost 10.5.0 through 10.5.10 and 10.11.0 through 10.11.2 allows remote authenticated users to recover secrets. Cloud API key and OAuth client-secret validation paths compare attacker-supplied values without constant-time handling, so response-time differences reveal matching bytes. A low-privileged remote account and repeated measurements are required; successful analysis discloses the compared secret without altering data or interrupting the service.

The record

CVE
CVE-2025-54499
Published
Oct 16, 2025
Updated
Oct 16, 2025
Vendor
Mattermost
Product
Mattermost
Classifications
CWE-208, T1110
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 16, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 16, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=10.11.0 <=10.11.2
  2. Affected versionversion=10.5.0 <=10.5.10

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Mattermost · Mattermostversion=10.11.0 <=10.11.2; version=10.5.0 <=10.5.10

Published CVSS scores

3.1Mattermost, Inc.CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N
3.7NIST NVDCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-208Observable Timing Discrepancy
T1110Brute Force

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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