vulnerability / NVI-00010647 / Revision 3
LiquidJS's strip_html filter bypass via newline characters in HTML tags enables XSS
GitHub lists this reviewed advisory for liquidjs. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
6.1 medium
GitHub source severity; exploitability and local consequence require separate evidence.
As of · GitHub Advisory Database
0.250%
FIRST EPSS model v2026.06.15; exploitation probability over 30 days, percentile 0.16344. Missing scores are unknown.
As of · FIRST EPSS
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
liquidjs
source listed< 10.26.0
## Summary The `strip_html` filter in liquidjs is intended to remove HTML tags from a string before rendering, and is widely used as an XSS sanitizer. The implementation uses a regex whose catch-all branch (``) does not match line terminators, so any HTML tag containing a `\n` or `\r` character passes through unmodified. An attacker who can place a newline inside a tag (e.g. ``) bypasses sanitization entirely, since browsers treat newlines as whitespace within a tag and execute the resulting `onerror`/`onload`/etc. handler. This results in stored or reflected XSS in any application that relies on `strip_html` to neutralize untrusted HTML. ## Details The vulnerable code is in `src/filters/html.ts`: ```ts // src/filters/html.ts:45-49 export function strip_html (this: FilterImpl, v: string) { const str = stringify(v) this.context.memoryLimit.use(str.length) return str.replace(/|||/g, '') } ``` The regex has four alternations: 1. `` — uses `[\s\S]`, matches across newlines. 2. `` — uses `[\s\S]`, matches across newlines. 3. `<
liquidjs
source listedSEMVER: introduced 0; fixed 10.26.0
## Summary The `strip_html` filter in liquidjs is intended to remove HTML tags from a string before rendering, and is widely used as an XSS sanitizer. The implementation uses a regex whose catch-all branch (``) does not match line terminators, so any HTML tag containing a `\n` or `\r` character passes through unmodified. An attacker who can place a newline inside a tag (e.g. ``) bypasses sanitization entirely, since browsers treat newlines as whitespace within a tag and execute the resulting `onerror`/`onload`/etc. handler. This results in stored or reflected XSS in any application that relies on `strip_html` to neutralize untrusted HTML. ## Details The vulnerable code is in `src/filters/html.ts`: ```ts // src/filters/html.ts:45-49 export function strip_html (this: FilterImpl, v: string) { const str = stringify(v) this.context.memoryLimit.use(str.length) return str.replace(/|||/g, '') } ``` The regex has four alternations: 1. `` — uses `[\s\S]`, matches across newlines. 2. `` — uses `[\s\S]`, matches across newlines. 3. `<
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. FIRST EPSS
- vendor patch
The original advisory lists fixed boundaries 10.26.0 for liquidjs. Confirm the publisher’s latest guidance.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database via OSV
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-2qv6-9wx5-cwv4 ↗
GitHub Advisory Database · vendor advisory
Observed . GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.
- GHSA-2qv6-9wx5-cwv4 ↗
GitHub Advisory Database via OSV · vendor advisory
Observed . GitHub-origin advisory, CC-BY-4.0; OSV is an aggregate copy, not independent corroboration.
- CVE-2026-44644 ↗
FIRST EPSS · official catalog
Observed . FIRST EPSS; probability of exploitation in the next 30 days, not local compromise. Dataset date/model retained; FIRST services terms apply.
Public revision history
Only published revisions appear here. Routine fetches do not create a material-change event.
- Revision 3 ·
Dated EPSS estimate updated; this is not a new disclosure or proof of exploitation.
- Revision 2 ·
Source facts changed; compare the preserved prior revision.
- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.