Skip to content
Patch Next
Sign inAdd to your agent

← Actionable
High, CVSS 8.6amended

matrix-js-sdk subject to user spoofing via Olm/Megolm protocol confusion

CVE-2022-39251GHSA-r48r-j8fx-mq2c

What to do

Vendor fix available. Upgrade each affected package to the fixed version on its release line (matrix-js-sdk 19.7.0), redeploy, then verify what is actually installed.

This page has no inventory attached, so it cannot say whether you are affected. A vendor fix is not proof that your deployment is fixed.

Add to your agent

Affected packages

Sources

Severity and exploitation
Exploitation
No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.
CVSS
8.6 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N
EPSS
  • CVE-2022-39251: 1.18% estimated exploitation activity in the next 30 days; percentile 67.63 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.
Source description

As published by the source; long descriptions are shortened.

Impact An attacker cooperating with a malicious homeserver can construct messages that legitimately appear to have come from another person, without any indication such as a grey shield. Additionally, a sophisticated attacker cooperating with a malicious homeserver could employ this vulnerability to perform a targeted attack in order to send fake to-device messages appearing to originate from another user. This can allow, for example, to inject the key backup secret during a self-verification, to make a targeted device start using a malicious key backup spoofed by the homeserver. These attacks are possible due to a protocol confusion vulnerability that accepts to-device messages encrypted with Megolm instead of Olm. Patches matrix-js-sdk has been modified to only accept Olm-encrypted to-device messages. Out of caution, several other checks have been audited or added: - Cleartext m.roomkey, m.forwardedroomkey and m.secret.send todevice messages are discarded. - Secrets received from…

Dates and revisions
Published by the source
Last modified by the source
Source last checked
  1. Revision 2 · amended ·

    Amended from ghsa record GHSA-r48r-j8fx-mq2c

  2. Revision 1 · created ·

    Published from osv record GHSA-r48r-j8fx-mq2c

Agent brief

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2022-39251

Advisory: matrix-js-sdk subject to user spoofing via Olm/Megolm protocol confusion
IDs: CVE-2022-39251, GHSA-r48r-j8fx-mq2c
Record: https://patchnext.com/advisories/cve-2022-39251 (revision 2, source checked 26 Oct 2026, 12:17 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.6)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: matrix-js-sdk 19.7.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm matrix-js-sdk: affected < 19.7.0; fixed in 19.7.0

## Suggested inspection (read-only)
- `npm ls matrix-js-sdk --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on matrix-js-sdk.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-r48r-j8fx-mq2c (OSV record GHSA-r48r-j8fx-mq2c lists affected ranges: npm matrix-js-sdk >=0 <19.7.0 (fixed))
- Verified: https://github.com/advisories/GHSA-r48r-j8fx-mq2c (GitHub-reviewed advisory GHSA-r48r-j8fx-mq2c lists affected ranges: npm matrix-js-sdk >=0 <19.7.0)

Commands are suggestions: review each one before running it.

Loading voting…