CVE-2025-54499: Github.com/mattermost/mattermost/server/v8 Mattermost Has An Observable Timing Vulnerability
LOWCVE-2025-54499 is a LOW (CVSS 3.1) mattermost has an observable timing vulnerability (CWE-208: Observable Timing Discrepancy) affecting Github.com/mattermost/mattermost/server/v8 libraries in the Go ecosystem. The issue involves mattermost has an observable timing discrepancy vulnerability. Remediation is available by upgrading affected packages to version 8.0.0-20250728063359-38208b8f065f, 10.5.11, 10.11.3.
CVE-2025-54499 at a Glance
Security Impact
CVSS: 3.1
The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N).
How to Fix CVE-2025-54499
To remediate this vulnerability, upgrade all affected Github.com/mattermost/mattermost/server/v8 dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
Upgrade github.com/mattermost/mattermost/server/v8 to 8.0.0-20250728063359-38208b8f065fUpgrade github.com/mattermost/mattermost-server to 10.5.11Upgrade github.com/mattermost/mattermost-server to 10.11.3Run the following command in your project directory to verify that all resolved dependencies use the patched release:
inspect dependencies for github.com/mattermost/mattermost/server/v8How to Check if You Are Affected
To determine whether your application is affected by CVE-2025-54499, inspect your project dependencies for Github.com/mattermost/mattermost/server/v8:
inspect dependencies for github.com/mattermost/mattermost/server/v8Analyze the terminal output to locate any version of Github.com/mattermost/mattermost/server/v8 in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 8.0.0-20250728063359-38208b8f065f), your application is affected.
Note: Verify declared build manifests and deployed runtime container environments.
Technical Details
Vulnerability Mechanism & Technical Analysis
This vulnerability is classified under CWE-208: Observable Timing Discrepancy, where two separate operations in a product require different amounts of time to complete, in a way that is observable to an actor and reveals security-relevant information about the state of the product, such as whether a particular operation was successful or not. In Github.com/mattermost/mattermost/server/v8, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.
Source Advisory Statement
CVE-2025-54499 Affected Github.com/mattermost/mattermost/server/v8 Versions
3 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
github.com/mattermost/mattermost/server/v8
|
Go |
< 8.0.0-20250728063359-38208b8f065f
|
8.0.0-20250728063359-38208b8f065f
|
|
github.com/mattermost/mattermost-server
|
Go |
≥ 10.5.0
< 10.5.11
|
10.5.11
|
|
github.com/mattermost/mattermost-server
|
Go |
≥ 10.11.0
< 10.11.3
|
10.11.3
|
References
Frequently Asked Questions
What is CVE-2025-54499?
Which Github.com/mattermost/mattermost/server/v8 versions are affected?
What version fixes CVE-2025-54499?
Is github.com/mattermost/mattermost/server/v8 affected?
Is github.com/mattermost/mattermost-server affected?
What is the CVSS score of CVE-2025-54499?
What CWE is associated with CVE-2025-54499?
How can I check Go dependencies for CVE-2025-54499?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-xr3w-rmvj-f6m7",
"modified" : "2025-10-16T21:04:21Z",
"published" : "2025-10-16T09:30:24Z",
"aliases" : [ "CVE-2025-54499" ],
"summary" : "Mattermost has an Observable Timing Discrepancy vulnerability",
"details" : "Mattermost versions 10.5.x <= 10.5.10, 10.11.x <= 10.11.2 fail to use constant-time comparison for sensitive string comparisons which allows attackers to exploit timing oracles to perform byte-by-byte brute force attacks via response time analysis on Cloud API keys and OAuth client secrets.",
"severity" : [ {
"type" : "CVSS_V3",
"score" : "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "Go",
"name" : "github.com/mattermost/mattermost/server/v8"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "8.0.0-20250728063359-38208b8f065f"
} ]
} ]
}, {
"package" : {
"ecosystem" : "Go",
"name" : "github.com/mattermost/mattermost-server"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "10.5.0"
}, {
"fixed" : "10.5.11"
} ]
} ]
}, {
"package" : {
"ecosystem" : "Go",
"name" : "github.com/mattermost/mattermost-server"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "10.11.0"
}, {
"fixed" : "10.11.3"
} ]
} ]
} ],
"references" : [ {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-54499"
}, {
"type" : "WEB",
"url" : "https://github.com/mattermost/mattermost/commit/38208b8f065f0786eac0e968f9d754b91b62878c"
}, {
"type" : "WEB",
"url" : "https://github.com/mattermost/mattermost/commit/97a4c7839cf5610cfe17c52042878aebb7678372"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/mattermost/mattermost"
}, {
"type" : "WEB",
"url" : "https://mattermost.com/security-updates"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-208" ],
"severity" : "LOW",
"github_reviewed" : true,
"github_reviewed_at" : "2025-10-16T21:04:21Z",
"nvd_published_at" : "2025-10-16T09:15:34Z"
}
}