Uptime Kuma's Regular Expression in pushdeeer and whapi file Leads to ReDoS Vulnerability Due to Catastrophic Backtracking

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

6.7 · CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:A/VC:N/VI:N/VA:H/SC:L/SI:L/SA:L · score source

EPSS

• CVE-2025-26042: 0.40% estimated exploitation activity in the next 30 days; percentile 33.94 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary There is a ReDoS vulnerability risk in the system, specifically when administrators create notification through the web service(pushdeer and whapi). If a string is provided that triggers catastrophic backtracking in the regular expression, it may lead to a ReDoS attack. Details The regular expression \/$\ is used to match zero or more slashes / at the end of a URL. When a malicious attack string appends a large number of slashes / and a non-slash character at the end of the URL, the regular expression enters a backtracking matching process. During this process, the regular expression engine starts checking each slash from the first one, continuing until it encounters the last non-slash character. Due to the greedy matching nature of the regular expression, this process repeats itself, with each backtrack checking the next slash until the last slash is checked. This backtracking process consumes significant CPU resources. For the regular expression /\/$/, an attack string like…

Published by the source

31 Mar 2025, 16:12 UTC

Last modified by the source

7 Aug 2025, 14:42 UTC

Source last checked

26 Oct 2026, 12:37 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-hx7h-9vf7-5xhg

2. Revision 2 · amended · 24 Oct 2026

   Reviewed OSV alias/range/CVSS4 correction; package source scopes and original publication preserved. No customer finding resolved.

3. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-hx7h-9vf7-5xhg

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# Patch Next advisory brief: CVE-2025-26042

Advisory: Uptime Kuma's Regular Expression in pushdeeer and whapi file Leads to ReDoS Vulnerability Due to Catastrophic Backtracking
IDs: CVE-2025-26042, GHSA-hx7h-9vf7-5xhg
Record: https://patchnext.com/advisories/cve-2025-26042 (revision 3, source checked 26 Oct 2026, 12:37 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.7)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Partial vendor fix; fixed versions by package: uptime-kuma 2.0.0-beta.2. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm uptime-kuma: affected >= 1.15.0, <= 1.23.16; >= 2.0.0-beta.0, < 2.0.0-beta.2; fixed in 2.0.0-beta.2

## Suggested inspection (read-only)
- `npm ls uptime-kuma --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on uptime-kuma.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-hx7h-9vf7-5xhg (OSV record GHSA-hx7h-9vf7-5xhg lists affected ranges: npm uptime-kuma >=1.15.0 =2.0.0-beta.0 <2.0.0-beta.2 (fixed))
- Verified: https://github.com/advisories/GHSA-hx7h-9vf7-5xhg (GitHub-reviewed advisory GHSA-hx7h-9vf7-5xhg lists affected ranges: npm uptime-kuma >=1.15.0 =2.0.0-beta.0 <2.0.0-beta.2)

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