# CVE-2022-39250: Matrix JavaScript SDK vulnerable to key/device identifier confusion in SAS verification > An attacker with a malicious homeserver can bypass SAS verification to inject their own identity, causing devices to trust the attacker instead of the intended user. - **Severity:** High 8.6 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 29 Sep 2022 - **Updated:** 23 Apr 2025 - **Also known as:** CLEANSTART-2024-YV48715, DEBIAN-CVE-2022-39250, GHSA-5w8r-8pgj-5jmf, UBUNTU-CVE-2022-39250 ## What is CVE-2022-39250? CVE-2022-39250 is a high-severity authentication bypass vulnerability in matrix-org matrix-js-sdk, published on 29 Sep 2022. An attacker can exploit it over the internet without logging in, with no action from the victim. ### Official description Matrix JavaScript SDK is the Matrix Client-Server software development kit (SDK) for JavaScript. Prior to version 19.7.0, an attacker cooperating with a malicious homeserver could interfere with the verification flow between two users, injecting its own cross-signing user identity in place of one of the users’ identities. This would lead to the other device trusting/verifying the user identity under the control of the homeserver instead of the intended one. The vulnerability is a bug in the matrix-js-sdk, caused by checking and signing user identities and devices in two separate steps, and inadequately fixing the keys to be signed between those steps. Even though the attack is partly made possible due to the design decision of treating cross-signing user identities as Matrix devices on the server side (with their device ID set to the public part of the user identity key), no other examined implementations were vulnerable. Starting with version 19.7.0, the matrix-js-sdk has been modified to double check that the key signed is the one that was verified instead of just referencing the key by ID. An additional check has been made to report an error when one of the device ID matches a cross-signing key. As this attack requires coordination between a malicious homeserver and an attacker, those who trust their homeservers do not need a particular workaround. Weakness: CWE-322 (Key Exchange without Entity Authentication), CWE-287 (Improper Authentication) ## Which versions are affected by CVE-2022-39250? 2 open source packages ship an affected version, including matrix-js-sdk. It affects 1 product. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `matrix-js-sdk` | npm | All versions | 19.7.0 | | `matrix-js-sdk` | npm | All versions | 19.7.0 | Products: Matrix Javascript Sdk. ## How do I fix CVE-2022-39250? Upgrade matrix-js-sdk to 19.7.0 or later. ## Is CVE-2022-39250 being exploited? There is no known exploitation of CVE-2022-39250 in the wild and no public exploit code. ## Other vulnerabilities in matrix-org matrix-js-sdk - [CVE-2022-39251](https://insights.sbomify.com/CVE-2022-39251/): Matrix Javascript SDK vulnerable to Olm/Megolm protocol confusion (high 8.6) - [CVE-2022-36059](https://insights.sbomify.com/CVE-2022-36059/): Prototype pollution in matrix-js-sdk (high 8.2) - [CVE-2023-28427](https://insights.sbomify.com/CVE-2023-28427/): Prototype pollution in matrix-js-sdk (high 8.2) - [CVE-2022-39249](https://insights.sbomify.com/CVE-2022-39249/): Matrix Javascript SDK vulnerable to impersonation via forwarded Megolm sessions (high 7.5) - [CVE-2021-40823](https://insights.sbomify.com/CVE-2021-40823/): matrix-js-sdk can be tricked into disclosing E2EE room keys to a participating homeserver (medium 5.9) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2022-39250 and fix it if it is affected. What it is: CVE-2022-39250 is a high-severity authentication bypass vulnerability in matrix-org matrix-js-sdk, published on 29 Sep 2022. An attacker can exploit it over the internet without logging in, with no action from the victim. Exploitation: There is no known exploitation of CVE-2022-39250 in the wild and no public exploit code. Affected packages and fixed versions: - matrix-js-sdk (npm): affected all versions; fixed in 19.7.0 - matrix-js-sdk (npm): affected all versions; fixed in 19.7.0 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-2022-39250/ (Markdown: https://insights.sbomify.com/CVE-2022-39250/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2022-39250 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-39250 - OSV: https://osv.dev/vulnerability/CVE-2022-39250 --- From sbomify Insights: https://insights.sbomify.com/CVE-2022-39250/ Summaries are generated and may contain mistakes; the official description above is the record.