CVE-2025-26042 is a medium-severity (CVSS 6) CWE-1333 vulnerability in uptime-kuma. A fix is available for uptime-kuma — see the affected versions and patch details below.
Uptime Kuma's Regular Expression in pushdeeer and whapi file Leads to ReDoS Vulnerability Due to Catastrophic Backtracking
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for CVE-2025-26042.
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-2025-26042 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 377,333 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.
uptime-kumanpmDescription
Uptime Kuma >== 1.23.0 has a ReDoS vulnerability, specifically when an administrator creates a notification through the web service. If a string is provided it triggers catastrophic backtracking in the regular expression, leading to a ReDoS attack.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | uptime-kuma | ≥ 1.15.0 | No fix |
| 📦npm | uptime-kuma | ≥ 2.0.0-beta.0&&< 2.0.0-beta.2 | 2.0.0-beta.2npm install uptime-kuma@2.0.0-beta.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for uptime-kuma, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
No patched version of uptime-kuma has shipped for CVE-2025-26042 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
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-2025-26042 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2025-26042. 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-2025-26042 in your dependencies?
O3 Security finds CVE-2025-26042 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.