CVE-2026-40897 is a high-severity (CVSS 8.8) CWE-915 vulnerability in mathjs. A fix is available for mathjs — see the affected versions and patch details below.
Math.js: Unsafe object property setter in mathjs
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- 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-2026-40897.
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-2026-40897 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.
mathjsnpmDescription
Impact
This security vulnerability allowed executing arbitrary JavaScript via the expression parser of mathjs. You can be affected when you have an application where users can evaluate arbitrary expressions using the mathjs expression parser.
Patches
The issue was introduced in mathjs v13.1.1, and patched in mathjs v15.2.0.
Workarounds
There is no workaround without upgrading to v15.2.0.
References
You can find out more via the commit fixing this issue: https://github.com/josdejong/mathjs/commit/513ab2a0e01004af91b31aada68fae8a821326ad (part of PR https://github.com/josdejong/mathjs/pull/3656).
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | mathjs | ≥ 13.1.1&&< 15.2.0 | 15.2.0npm install mathjs@15.2.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for mathjs, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update mathjs to 15.2.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-40897 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-2026-40897 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-40897. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-40897 in your dependencies?
O3 Security finds CVE-2026-40897 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.