CVE-2023-28427 — matrix-js-sdk
HIGHCVE-2023-28427 is a high-severity (CVSS 8.2) CWE-1321 vulnerability in matrix-js-sdk. A fix is available for matrix-js-sdk — see the affected versions and patch details below.
Prototype pollution in matrix-js-sdk
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-2023-28427.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2023-28427 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,636 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
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.
matrix-js-sdknpmDescription
Impact
In certain configurations, data sent by remote servers containing special strings in key locations could cause modifications of the Object.prototype, disrupting matrix-js-sdk functionality, causing denial of service and potentially affecting program logic.
(This is part 2, where CVE-2022-36059 / GHSA-rfv9-x7hh-xc32 is part 1. Part 2 covers remaining vectors not covered by part 1, found in a codebase audit scheduled after part 1.)
Patches
The issue has been patched in matrix-js-sdk 24.0.0.
Workarounds
None.
References
- Release blog post
- The advisory GHSA-rfv9-x7hh-xc32 (CVE-2022-36059) refers to an initial set of vulnerable locations discovered and patched in matrix-js-sdk 19.4.0. We opted not to disclose that advisory while we performed an audit of the codebase and are now disclosing it jointly with this one.
For more information
If you have any questions or comments about this advisory please email us at security at matrix.org.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | matrix-js-sdk | all versions | 24.0.0npm install matrix-js-sdk@24.0.0 |
Detection & mitigation playbook
Open-source dependencyDetect
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 24.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-28427 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2023-28427 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2023-28427. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
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 Hat Product Security rates the severity of this flaw as determined by the Mozilla Foundation Security Advisory.
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Enterprise Linux 7 | thunderbird-0:102.10.0-2.el7_9 | RHSA-2023:1806 |
| Red Hat Enterprise Linux 8 | thunderbird-0:102.10.0-2.el8_7 | RHSA-2023:1802 |
| Red Hat Enterprise Linux 8.1 Update Services for SAP Solutions | thunderbird-0:102.10.0-2.el8_1 | RHSA-2023:1803 |
| Red Hat Enterprise Linux 8.2 Advanced Update Support | thunderbird-0:102.10.0-2.el8_2 | RHSA-2023:1805 |
| Red Hat Enterprise Linux 8.4 Extended Update Support | thunderbird-0:102.10.0-2.el8_4 | RHSA-2023:1804 |
| Red Hat Enterprise Linux 8.6 Extended Update Support | thunderbird-0:102.10.0-2.el8_6 | RHSA-2023:1811 |
| Red Hat Enterprise Linux 9 | thunderbird-0:102.10.0-2.el9_1 | RHSA-2023:1809 |
| Red Hat Enterprise Linux 9.0 Extended Update Support | thunderbird-0:102.10.0-2.el9_0 | RHSA-2023:1810 |
Frequently Asked Questions
Is CVE-2023-28427 in your dependencies?
O3 Security finds CVE-2023-28427 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.