{"id":"CVE-2021-39178","aliases":["GHSA-9gr3-7897-pp7m"],"url":"https://o3.security/vulnerability/CVE-2021-39178","summary":"XSS in Image Optimization API for Next.js","details":"Next.js is a React framework. Versions of Next.js between 10.0.0 and 11.0.0 contain a cross-site scripting vulnerability. In order for an instance to be affected by the vulnerability, the `next.config.js` file must have `images.domains` array assigned and the image host assigned in `images.domains` must allow user-provided SVG. If the `next.config.js` file has `images.loader` assigned to something other than default or the instance is deployed on Vercel, the instance is not affected by the vulnerability. The vulnerability is patched in Next.js version 11.1.1.","published":"2021-08-31T00:15:07.203Z","modified":"2026-07-09T10:52:23.270722Z","cvss":{"score":6.1,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"next","fixedVersion":"11.1.1"}],"fix":null,"references":[{"type":"FIX","url":"https://github.com/vercel/next.js/releases/tag/v11.1.1"},{"type":"FIX","url":"https://github.com/vercel/next.js/security/advisories/GHSA-9gr3-7897-pp7m"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-09T10:52:23.270722Z"}}