# CVE-2025-54499: Insecure string comparison enables timing attacks > Attackers can exploit timing oracles to brute-force Cloud API keys and OAuth client secrets, leading to credential disclosure and potential account takeover. - **Severity:** Low 3.1 (`CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N`) - **Exploited in the wild:** Not known - **Login needed:** Any signed-in user - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 16 Oct 2025 - **Updated:** 16 Oct 2025 - **Also known as:** GHSA-xr3w-rmvj-f6m7, GO-2025-4036 ## What is CVE-2025-54499? CVE-2025-54499 is a low-severity vulnerability in Mattermost Mattermost Server, published on 16 Oct 2025. Any signed-in user can exploit it over the network, with no action from the victim. ### Official description 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 Weakness: CWE-208 (Observable Timing Discrepancy) ## Which versions are affected by CVE-2025-54499? 10 open source packages ship an affected version, including github.com/mattermost/mattermost-server, github.com/mattermost/mattermost-server/v5 and github.com/mattermost/mattermost-server/v6. It affects 1 product. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `github.com/mattermost/mattermost-server` | Go | From 10.11.0 | 10.11.3 | | `github.com/mattermost/mattermost-server` | Go | From 10.11.0 | 10.11.3 | | `github.com/mattermost/mattermost-server` | Go | From 10.5.0 | 10.5.11 | | `github.com/mattermost/mattermost-server` | Go | From 10.5.0 | 10.5.11 | | `github.com/mattermost/mattermost-server` | Go | From 10.5.0+incompatible | 10.5.11+incompatible, 10.11.3+incompatible | | `github.com/mattermost/mattermost-server/v5` | Go | All versions | None | | `github.com/mattermost/mattermost-server/v6` | Go | All versions | None | | `github.com/mattermost/mattermost/server/v8` | Go | All versions | 8.0.0-20250728063359-38208b8f065f | | `github.com/mattermost/mattermost/server/v8` | Go | All versions | 8.0.0-20250728063359-38208b8f065f | | `github.com/mattermost/mattermost/server/v8` | Go | All versions | 8.0.0-20250728063359-38208b8f065f | Products: Mattermost Mattermost Server. ## How do I fix CVE-2025-54499? Upgrade github.com/mattermost/mattermost-server to a fixed version for your release line: 10.11.3, 10.5.11, 10.5.11+incompatible or 10.11.3+incompatible. ## Is CVE-2025-54499 being exploited? There is no known exploitation of CVE-2025-54499 in the wild and no public exploit code. ## Other vulnerabilities in Mattermost Mattermost Server - [CVE-2025-12419](https://insights.sbomify.com/CVE-2025-12419/): Account takeover on OAuth/OpenID-enabled servers (critical 9.9) - [CVE-2025-12421](https://insights.sbomify.com/CVE-2025-12421/): Account Takeover via Code Exchange Endpoint (critical 9.9) - [CVE-2025-4981](https://insights.sbomify.com/CVE-2025-4981/): Path Traversal Leading to RCE by Any Authenticated Mattermost User (critical 9.9) - [CVE-2025-20051](https://insights.sbomify.com/CVE-2025-20051/): Arbitrary file read via block duplication in Mattermost Boards (critical 9.9) - [CVE-2025-25279](https://insights.sbomify.com/CVE-2025-25279/): Arbitrary file read in Mattermost Boards via import & export board archive (critical 9.9) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2025-54499 and fix it if it is affected. What it is: CVE-2025-54499 is a low-severity vulnerability in Mattermost Mattermost Server, published on 16 Oct 2025. Any signed-in user can exploit it over the network, with no action from the victim. Exploitation: There is no known exploitation of CVE-2025-54499 in the wild and no public exploit code. Affected packages and fixed versions: - github.com/mattermost/mattermost-server (Go): affected from 10.11.0; fixed in 10.11.3 - github.com/mattermost/mattermost-server (Go): affected from 10.11.0; fixed in 10.11.3 - github.com/mattermost/mattermost-server (Go): affected from 10.5.0; fixed in 10.5.11 - github.com/mattermost/mattermost-server (Go): affected from 10.5.0; fixed in 10.5.11 - github.com/mattermost/mattermost-server (Go): affected from 10.5.0+incompatible; fixed in 10.5.11+incompatible, 10.11.3+incompatible - github.com/mattermost/mattermost-server/v5 (Go): affected all versions; no fix listed - github.com/mattermost/mattermost-server/v6 (Go): affected all versions; no fix listed - github.com/mattermost/mattermost/server/v8 (Go): affected all versions; fixed in 8.0.0-20250728063359-38208b8f065f - github.com/mattermost/mattermost/server/v8 (Go): affected all versions; fixed in 8.0.0-20250728063359-38208b8f065f - github.com/mattermost/mattermost/server/v8 (Go): affected all versions; fixed in 8.0.0-20250728063359-38208b8f065f Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2025-54499/ (Markdown: https://insights.sbomify.com/CVE-2025-54499/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2025-54499 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-54499 - OSV: https://osv.dev/vulnerability/CVE-2025-54499 --- From sbomify Insights: https://insights.sbomify.com/CVE-2025-54499/ Summaries are generated and may contain mistakes; the official description above is the record.