How severe is CVE-2022-39250?

CVE-2022-39250 has a CVSS score of 8.6/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2022-39250?

CVE-2022-39250 affects the following packages: matrix-js-sdk (npm). Ecosystems affected: npm.

How do I fix CVE-2022-39250?

Update matrix-js-sdk to 19.7.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2022-39250 is resolved across your whole dependency graph.

How do I detect CVE-2022-39250 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for matrix-js-sdk, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2022-39250 if there is no patch (or I can't update yet)?

Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Is CVE-2022-39250 actively exploited in the wild?

No public exploit code has been indexed for CVE-2022-39250 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2022-39250?

CVE-2022-39250 has an EPSS (Exploit Prediction Scoring System) score of 1.2%, placing it in the 68th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2022-39250?

CVE-2022-39250 is classified as Improper Authentication (CWE-287), CWE-322 (CWE-322). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2022-39250 published, and has it been updated?

CVE-2022-39250 was published on September 29, 2022 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦

📦 npm

Not in CISA KEV

HIGH severity

CVE-2022-39250 — matrix-js-sdk

HIGHFix: matrix-org/matrix-js-sdk@a587d7c

CVE-2022-39250 is a high-severity (CVSS 8.6) Improper Authentication vulnerability in matrix-js-sdk. A fix is available for matrix-js-sdk — see the affected versions and patch details below.

Matrix JavaScript SDK vulnerable to key/device identifier confusion in SAS verification

Also known asGHSA-5w8r-8pgj-5jmf

Published

Sep 29, 2022

Updated

Oct 28, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 4, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2022-39250.

EPSS Exploitation Probability

via FIRST.org ↗

1.2%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs68th percentile — riskier than 68% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

1 pkg affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.

167other npm packages depend on this — each one inherits the vulnerability until it's patched upstream

matrix-js-sdknpm

469Kdownloads / week

Description

Impact

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, leading 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.

Patches

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.

Workarounds

As this attack requires coordination between a malicious homeserver and an attacker -- if you trust your homeserver no particular workaround is needed.

As a potential way of detecting compromise, it’s possible to review your device list or the device list of other users for devices with IDs in the form of a base64 cross-signing key (5XaczGNlfz0bl8R1IX5qn+tBoue2tWJqLMh+SDUuvCk) instead of classical device ID (SEHACYDHMG).

References

Blog post: https://matrix.org/blog/2022/09/28/upgrade-now-to-address-encryption-vulns-in-matrix-sdks-and-clients

For more information

If you have any questions or comments about this advisory, e-mail us at [email protected]

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`matrix-js-sdk`	all versions	19.7.0`npm install matrix-js-sdk@19.7.0`

Affected Products

1 product · 1 configurations

Application

javascript sdkmatrix

< 19.7.0

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for matrix-js-sdk, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update matrix-js-sdk to 19.7.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2022-39250 is resolved across your whole dependency graph.
Workarounds
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatImportant

Product	Fixed in	Advisory
Red Hat Enterprise Linux 7	`thunderbird-0:102.4.0-1.el7_9`	RHSA-2022:7184
Red Hat Enterprise Linux 8	`thunderbird-0:102.4.0-1.el8_6`	RHSA-2022:7190
Red Hat Enterprise Linux 8.1 Update Services for SAP Solutions	`thunderbird-0:102.4.0-1.el8_1`	RHSA-2022:7183
Red Hat Enterprise Linux 8.2 Extended Update Support	`thunderbird-0:102.4.0-1.el8_2`	RHSA-2022:7182
Red Hat Enterprise Linux 8.4 Extended Update Support	`thunderbird-0:102.4.0-1.el8_4`	RHSA-2022:7181
Red Hat Enterprise Linux 9	`thunderbird-0:102.4.0-1.el9_0`	RHSA-2022:7178

Frequently Asked Questions

## Impact 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, leading 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