LiquidJS has an infinite loop vulnerability in its strip_html filter

Exploitation

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

CVSS 4.0

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

EPSS

• CVE-2026-61556: 0.52% estimated exploitation activity in the next 30 days; percentile 44.47 (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 The current implementation of striphtml can cause an infinite loop when the input string contains <, has at least one character before <, and no appears after <. Details The problem is in src/filters/html.ts. Specifically, the following part has the infinite loop. For the input "a<", the variable lt is updated to 1 by const lt = str.indexOf('<', i). However, the variable i is never updated from its initial value of 0. This is because in const e = str.indexOf(closer, lt + opener.length), e becomes -1, since there is no after <. Therefore, when execution reaches if (i === lt) return out + str.slice(lt), i is 0. This is the same state as at the beginning of the loop. As a result, the same thing is repeated again from that state, causing an infinite loop. PoC Impact This is an infinite loop vulnerability (cf. https://cwe.mitre.org/data/definitions/835.html). This results in a denial of service (DoS). Although a ReDoS vulnerability has previously been reported in the affected…

Published by the source

3 Sep 2026, 17:45 UTC

Last modified by the source

3 Sep 2026, 17:45 UTC

Source last checked

26 Oct 2026, 13:02 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-m7fp-h3p4-hr49

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# Patch Next advisory brief: CVE-2026-61556

Advisory: LiquidJS has an infinite loop vulnerability in its `strip_html` filter
IDs: CVE-2026-61556, GHSA-m7fp-h3p4-hr49
Record: https://patchnext.com/advisories/cve-2026-61556 (revision 1, source checked 26 Oct 2026, 13:02 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.7)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: liquidjs 10.27.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm liquidjs: affected >= 10.26.0, < 10.27.1; fixed in 10.27.1

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

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on liquidjs.
- 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://github.com/advisories/GHSA-m7fp-h3p4-hr49 (GitHub-reviewed advisory GHSA-m7fp-h3p4-hr49 lists affected ranges: npm liquidjs >=10.26.0 <10.27.1)

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