CVE-2023-23630: Cross-site (XSS) vulnerability with Express API in Eta

Severity: medium (CVSS 6.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.6% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2023-02-01 · updated 2026-06-17
Weakness: CWE-79

Description

Eta is an embedded JS templating engine that works inside Node, Deno, and the browser. XSS attack - anyone using the Express API is impacted. The problem has been resolved. Users should upgrade to version 2.0.0. As a workaround, don't pass user supplied things directly to `res.render`.

Affected products

eta: before 2.0.0 — fixed in 2.0.0

How to fix

Upgrade to a fixed version: eta 2.0.0. Check the vendor advisory for mitigations.

References

https://github.com/eta-dev/eta/commit/5651392462ee0ff19d77c8481081a99e5b9138dd
https://github.com/eta-dev/eta/releases/tag/v2.0.0
https://github.com/eta-dev/eta/security/advisories/GHSA-xrh7-m5pp-39r6
https://github.com/eta-dev/eta/commit/5651392462ee0ff19d77c8481081a99e5b9138dd
https://github.com/eta-dev/eta/releases/tag/v2.0.0
https://github.com/eta-dev/eta/security/advisories/GHSA-xrh7-m5pp-39r6

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