Evidence used
- No CISA KEV confirmation is currently recorded.
- The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
- EPSS is 1.18% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2022
CVE-2022-39250High confidence
Matrix JavaScript SDK vulnerable to key/device identifier confusion in SAS verification
matrix-org · matrix-js-sdk
8.6HighCVSS 3.1
Within 7 days
Patch availableHigh technical severity; prioritise exposed affected systems while verifying vendor guidance.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityHigh→Operational priority:High, unchanged from published severity.unchanged
Compensating controls
- Validate the affected product branch and deploy the verified fixed release.
- Restrict the affected network interface to trusted sources where business-safe.
- Monitor vendor guidance and exploitation sources for a material change.
Verification
- Confirm that the asset runs matrix-org matrix-js-sdk and falls inside the recorded affected range.
- Verify the installed build against the product-specific fixed version after deployment.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Distribution package intelligence
4 package statesRelease-specific package status
Alpine, ubuntu findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.
Repository candidate not checked
A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.
| Distribution release | Source package | Vendor state | Fixed version | Evidence |
|---|---|---|---|---|
| Alpine v3.23v3.23 · community | element-web | Vendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected. | 1.11.7-r0 | Alpine Security Database ↗Source updated 11 Sep 2026 |
| Alpine v3.22v3.22 · community | element-web | Vendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected. | 1.11.7-r0 | Alpine Security Database ↗Source updated 11 Sep 2026 |
| Alpine v3.21v3.21 · community | element-web | Vendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected. | 1.11.7-r0 | Alpine Security Database ↗Source updated 19 Aug 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | node-matrix-js-sdk | Under evaluationCanonical reports that the package might be affected and still needs evaluation or fixing. | Not published in this feed | Canonical Ubuntu Security ↗Source updated 5 Oct 2026 |
High technical severity; prioritise exposed affected systems while verifying vendor guidance.
Patch available01
What, why and how
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.
What
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.
Why
The product performs a key exchange with an actor without verifying the identity of that actor.
How
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
What
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.
Why
The product performs a key exchange with an actor without verifying the identity of that actor.
How
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
Public PoC / exploit material None recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.
- Likely attack path
- a network path → Key Exchange without Entity Authentication → cause the confidentiality, integrity or availability impact described by the vendor
- Attack surface
- Network
- Privileges required
- None: unauthenticated exploitation is possible
- User interaction
- None
- Attack complexity
- Low: no specialised conditions are recorded
- Security boundary
- Changed: exploitation can affect a different security authority
- Weakness
?
CWE means Common Weakness Enumeration: a standard category for the underlying weakness. - CWE-322 ↗
CWE-322: Key Exchange without Entity Authentication. The product performs a key exchange with an actor without verifying the identity of that actor.
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:NCommon Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SChangedScope: The attack can affect a component governed by a different security authority.CNoneConfidentiality impact: No direct loss is represented by this metric.IHighIntegrity impact: A successful attack can cause a major loss.ANoneAvailability impact: No direct loss is represented by this metric.- Post-exploitation / living off the land
- No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
03
Patch and workaround
Operational remediation based on structured source evidence.
- Status
?
Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change. - Patch available
- Affected
- matrix-js-sdk: < 19.7.0
- Action
- Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
- Workaround
- No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04
Evidence and provenance
Published 29 Sept 2022 · Last source change 23 Apr 2025, 16:54 UTC · CWE-322 · Key Exchange without Entity Authentication
CVE recordCVE.org · 5.1
CVSS sourceCNA
EPSS source FIRST · tracked since 2026-08-14
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2022-6713
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD modified after enrichment
Core structured fields are present and their contributing authorities are shown above.
Material change intelligence
View recent updates ↗What changed after publication
No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.
CVE published
Fixed release or patch reference recorded
Technical terms and abbreviations used in this report
- CVE
- Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
- CVSS
- Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
- EPSS
- Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
- CWE
- Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
- CNA
- CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
- CISA ADP
- Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
- NVD
- National Vulnerability Database: NIST's enrichment service for CVE records.
- CERT / CSIRT
- A computer security incident response team that publishes warnings or coordinates incident response.
- PoC
- Proof of concept: public material that demonstrates or helps reproduce exploitation.
- CSAF
- Common Security Advisory Framework: a machine-readable format for security advisories.
- LoTL
- Living off the land: abuse of legitimate tools or system functions during an attack.