LiquidJS has a memory and render limit bypass via unbounded width padding in date filter (strftime)

Exploitation

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

CVSS

7.5 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

• CVE-2026-45357: 0.39% estimated exploitation activity in the next 30 days; percentile 32.65 (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 `date` filter's strftime implementation parses width specifiers like `%9999999d` and forwards the captured width unchecked into `pad()`/`padStart()` in `src/util/underscore.ts`. The pad loop performs unbounded string concatenation without consulting the Context's `memoryLimit` or `renderLimit`, so a single small template (`{{ x | date: '%5000000d' }}`) produces megabytes of output and unbounded CPU. The `memoryLimit` and `renderLimit` options the docs (`src/liquid-options.ts:87-92`) advertise as DoS controls — and which the docstring explicitly mentions for `strftime` — are entirely bypassed.

Details `date.ts:5-13` only charges `memoryLimit` for the lengths of the input value, format string, and timezone: ```ts export function date (this: FilterImpl, v: string | Date, format?: string, timezoneOffset?: number | string) { const size = ((v as string)?.length ?? 0) + (format?.length ?? 0) + ((timezoneOffset as string)?.length ?? 0) this.context.memoryLimit.use(size) ...…

Published by the source

27 May 2026, 17:33 UTC

Last modified by the source

28 Oct 2026, 15:15 UTC

Source last checked

29 Oct 2026, 06:00 UTC

1. Revision 4 · amended · 29 Oct 2026

   Amended from osv record GHSA-hh27-hf48-9f5q

2. Revision 3 · amended · 28 Oct 2026

   Amended from ghsa record GHSA-hh27-hf48-9f5q

3. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-hh27-hf48-9f5q

4. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-hh27-hf48-9f5q

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# Patch Next advisory brief: CVE-2026-45357

Advisory: LiquidJS has a memory and render limit bypass via unbounded width padding in `date` filter (strftime)
IDs: CVE-2026-45357, GHSA-hh27-hf48-9f5q
Record: https://patchnext.com/advisories/cve-2026-45357 (revision 4, source checked 29 Oct 2026, 06:00 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: liquidjs 10.26.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm liquidjs: affected < 10.26.0; fixed in 10.26.0

## 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://osv.dev/vulnerability/GHSA-hh27-hf48-9f5q (OSV record GHSA-hh27-hf48-9f5q lists affected ranges: npm liquidjs >=0 <=10.25.7)
- Verified: https://github.com/advisories/GHSA-hh27-hf48-9f5q (GitHub-reviewed advisory GHSA-hh27-hf48-9f5q lists affected ranges: npm liquidjs >=0 <=10.25.7)
- Verified: https://osv.dev/vulnerability/GHSA-hh27-hf48-9f5q (OSV record GHSA-hh27-hf48-9f5q lists affected ranges: npm liquidjs >=0 <10.26.0 (fixed))

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