# LiquidJS: ownPropertyOnly bypass for inherited array indices in first/last/join/reverse/slice/compact, \`.first\`/\`.last\`, negative index, and for-loop iteration

Advisory record · `GHSA-fwxr-j5w2-587m`

- **Identifiers:** `GHSA-fwxr-j5w2-587m` · `CVE-2026-106120`
- **State:** Confirmed
- **Severity:** CVSS 6.0 Medium
- **Critical:** No
- **Weakness (CWE):** [CWE-200](https://cwe.mitre.org/data/definitions/200.html)
- **Tags:** [Information disclosure](https://agentprime.io/advisories/tag/info-disclosure.md)
- **Published:** 7 Oct 2026
- **Updated:** 7 Oct 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 7 Oct 2026, 16:19 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `liquidjs` (npm): affected `<10.27.2`; fixed in `10.27.2`

## Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

> LiquidJS versions before 10.27.2 fail to honor the ownPropertyOnly option for inherited array indices. When that option is enabled, values inherited through Array.prototype can still be read through array filters such as first, last, join, reverse, slice and compact, through the .first and .last properties, through negative indexing, and through for-loop iteration. An attacker who can influence prototype state or inherited array-index data could cause a template to disclose values that ownPropertyOnly is meant to hide. Upgrade liquidjs to 10.27.2 or later.

Written 31 Oct 2026.

## Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

## Severity and exploitation

- 6.0 Medium, CVSS 4.0: `CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N`, from CNA (GitHub_M)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0041, the 35th percentile, on 13 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 13:33 UTC: First seen by agentprime
- 31 Oct 2026, 13:33 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-fwxr-j5w2-587m)

## Sources

- [GitHub Advisory Database: GHSA-fwxr-j5w2-587m](https://github.com/advisories/GHSA-fwxr-j5w2-587m)
- [OSV: GHSA-fwxr-j5w2-587m](https://osv.dev/vulnerability/GHSA-fwxr-j5w2-587m)
- <https://github.com/harttle/liquidjs/security/advisories/GHSA-fwxr-j5w2-587m>
- <https://nvd.nist.gov/vuln/detail/CVE-2026-106120>
- <https://github.com/harttle/liquidjs/pull/924>
- <https://github.com/harttle/liquidjs/commit/552819a84b80c62306fe61072628a756272dc749>
- <https://github.com/harttle/liquidjs>
- <https://github.com/harttle/liquidjs/releases/tag/v10.27.2>

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-fwxr-j5w2-587m>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-fwxr-j5w2-587m/>. Everything for agents: <https://agentprime.io/llms.txt>.