# CVE-2026-42794: absinthe-graphql absinthe_plug reflected XSS in GraphiQL interface

Source: https://junglewise.ai/threats/cve-2026-42794-absinthe-graphql-absinthe-plug-reflected-xss-in-graphiql  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-08. Updated: 2026-06-09  
License: CC BY 4.0 with a link back

CVE-2026-42794 · Severity: medium · CVSS 6.1 · Published 2026-05-08

Absinthe Plug is a library used to provide a GraphQL interface for Elixir web applications. A security flaw in its GraphiQL tool allows attackers to run malicious scripts in a user's browser if the user clicks a specially crafted link. This could lead to unauthorized actions being performed on behalf of the user or the theft of sensitive session information.

Vendors: [Erlang](https://junglewise.ai/threats/vendors/erlang).

## Quick answers

**Is CVE-2026-42794 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-42794 being exploited in the wild.

**How severe is CVE-2026-42794?** Medium severity, with a CVSS score of 6.1, published 8 May 2026.

**Which products and versions are affected?** Absinthe GraphQL Plug >= 1.2.0, < 1.10.2; Erlang Absinthe Plug >= 1.2.0, <= 1.5.9.

**Is there a fix for CVE-2026-42794?** A patch was published on 2026-05-08: Fix committed to repository Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-42794 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-42794?** Check whether you run Absinthe GraphQL Plug or Erlang Absinthe Plug at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A reflected cross-site scripting (XSS) vulnerability exists in the GraphiQL interface of absinthe_plug. The 'js_escape/1' function in 'lib/absinthe/plug/graphiql.ex' fails to escape backslashes when processing the 'query' GET parameter before embedding it into an inline JavaScript string. An attacker can use a backslash to escape the subsequent single quote (e.g., \'), breaking out of the JavaScript string context to execute arbitrary code. This vulnerability is exploitable via a crafted URL and affects versions 1.2.0 through 1.5.9. A fix is available in version 1.5.10.

## Affected products

- absinthe-graphql absinthe_plug >= 1.2.0, < 1.5.10

## Identifiers

- CVE-2026-42794
- GHSA-c62g-j346-39v5

## Timeline

- 2022-10-14: disclosed: Issue first reported on GitHub
- 2026-05-08: advisory: GitHub Advisory published
- 2026-05-08: patched: Fix committed to repository

## References

- [https://github.com/absinthe-graphql/absinthe_plug/issues/275](https://github.com/absinthe-graphql/absinthe_plug/issues/275)
- [https://github.com/absinthe-graphql/absinthe_plug/commit/23a0d5658d32420086711adf4ce8f05febb09963](https://github.com/absinthe-graphql/absinthe_plug/commit/23a0d5658d32420086711adf4ce8f05febb09963)
- [https://cna.erlef.org/cves/CVE-2026-42794.html](https://cna.erlef.org/cves/CVE-2026-42794.html)