CVE-2026-45056

MEDIUMPre-NVD 6.96.9—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 6.9 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3% (21st percentile of EPSS-scored CVEs). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
6.9EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 6.9Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

matrix-sdk-crypto is a no-network-IO implementation of a state machine that handles end-to-end encryption for Matrix clients. Starting in version 0.12.0 and prior to version 0.17.0, the matrix-sdk-crypto crate was missing a check for the user ID when decrypting an Olm-encrypted event containing the sender_device_keys property. This could be exploited to forge an encrypted to-device event, but only if the attacker colludes with the homeserver operator. This issue is fixed in matrix-sdk-crypto 0.17.0. There are no known workarounds for the issue.

CVSS v3
6.9
EG Score
6.9MEDIUMmedium confidence
EG Risk
31
EG Risk 31/100CISA SSVC

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity69% × 45%
Exploitation0% × 40%
Automatability0% × 15%
CISA SSVC: Track at every mission impact level.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.3%
EPSS %ILE
21st
KEV
Not listed

CISA SSVCTrack at every mission impact level.

A fix is available. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

June 4, 2026

Last Modified

September 30, 2026

Advisory Details (4)

Auto-updated Sep 11, 2026
Patch available. Sources: github, github_pr, github_release.
generic

RUSTSEC-2026-0159: matrix-sdk-crypto: Sender-binding gaps in to-device messages › RustSec Advisory Database

https://rustsec.org/advisories/RUSTSEC-2026-0159.html
github_release Patch Available

matrix-sdk 0.16.1

Patch available: matrix-org/matrix-rust-sdk matrix-sdk-0.16.1

https://github.com/matrix-org/matrix-rust-sdk/releases/tag/matrix-sdk-0.16.1
github_pr Patch Available

Check the user ID in the embedded device keys

Patch available: matrix-org/matrix-rust-sdk matrix-sdk-0.17.0 (PR #6553 merged 2026-05-08)

https://github.com/matrix-org/matrix-rust-sdk/pull/6553
githubMentions a patch (unverified)

Sender-binding gaps in to-device messages allow for sender spoofing · Advisory · matrix-org/matrix-rust-sdk · GitHub

https://github.com/matrix-org/matrix-rust-sdk/security/advisories/GHSA-wfq4-36m3-9g42

Vendor Advisories for CVE-2026-45056(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(1 across 1 ecosystem)
crates.io(1)
PackageVulnerable rangeFix by version rangeDependents
matrix-sdk-crypto—
  • 0.12.0 up to 0.16.1: fixed in 0.16.1
—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 7× in last 7d / 27× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-10-10 20:00 UTCEPSS rescore
  2. 2026-10-09 20:07 UTCEPSS rescore
  3. 2026-10-08 17:12 UTCEPSS rescore
  4. 2026-10-07 23:48 UTCEPSS rescore
  5. 2026-10-06 15:18 UTCEPSS rescore
  6. 2026-10-05 17:43 UTCEPSS rescore
  7. 2026-10-04 23:22 UTCEPSS rescore
  8. 2026-10-03 14:25 UTCEPSS rescore
  9. 2026-10-01 19:50 UTCEPSS rescore
  10. 2026-09-30 20:05 UTCEG score recompute
  11. 2026-09-30 15:03 UTCEPSS rescore
  12. 2026-09-27 13:48 UTCEPSS rescore
  13. 2026-09-26 15:58 UTCEPSS rescore
  14. 2026-09-23 17:53 UTCEPSS rescore
  15. 2026-09-20 20:15 UTCEPSS rescore
  16. 2026-09-18 19:28 UTCEPSS rescore
  17. 2026-09-17 19:31 UTCEPSS rescore
  18. 2026-09-16 14:08 UTCEPSS rescore
  19. 2026-09-16 05:15 UTCEPSS rescore
  20. 2026-09-14 19:24 UTCEG score recompute
  21. 2026-09-14 18:28 UTCEG score recompute
  22. 2026-09-14 05:23 UTCEG score recompute
  23. 2026-09-13 16:47 UTCEPSS rescore
  24. 2026-09-12 15:01 UTCEPSS rescore
  25. 2026-09-11 23:11 UTCEG score recompute
Show 9 more
  1. 2026-09-11 21:24 UTCEG score recompute▲ 6.90
  2. 2026-09-11 21:23 UTCMITRE cvelistV5CVSS v3 → 6.9 · CVSS v4 → 6.9
  3. 2026-07-31 05:26 UTCEG score recompute
  4. 2026-07-26 22:16 UTCEG score recompute
  5. 2026-07-23 03:16 UTCEG score recompute
  6. 2026-06-14 23:18 UTCEPSS rescore
  7. 2026-06-13 23:00 UTCEPSS rescore
  8. 2026-06-12 23:12 UTCEPSS rescore
  9. 2026-06-04 15:10 UTCEG score recompute

Related CVEs(same product + same CWE)

Frequently asked(5)

What is CVE-2026-45056?
CVE-2026-45056 is a medium vulnerability published on June 4, 2026. matrix-sdk-crypto is a no-network-IO implementation of a state machine that handles end-to-end encryption for Matrix clients. Starting in version 0.12.0 and prior to version 0.17.0, the matrix-sdk-crypto crate was missing a check for the user ID when decrypting an Olm-encrypted event containing the…
When was CVE-2026-45056 disclosed?
CVE-2026-45056 was first published on June 4, 2026, with the most recent update on September 30, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-45056 actively exploited?
CVE-2026-45056 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (21st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-45056?
CVE-2026-45056 has a CVSS base score of 6.9 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-45056?
A fix for CVE-2026-45056 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-45056 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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