{"id":"CVE-2026-64641","aliases":["GHSA-m99w-x7hq-7vfj"],"title":"Next.js: Denial of Service in App Router using Server Actions","summary":"Next.js: Denial of Service in App Router using Server Actions","severity":"high","cwe":["CWE-834"],"vendor":"next","product":"next","ecosystem":"npm","affected":["next >= 13.0.0, < 15.5.21","next >= 16.0.0, < 16.2.11"],"patched":["next 15.5.21","next 16.2.11"],"published":"2026-07-22","updated":"2026-07-22","source":"GHSA","sourceUrl":"https://github.com/advisories/GHSA-m99w-x7hq-7vfj","references":[{"url":"https://github.com/vercel/next.js/security/advisories/GHSA-m99w-x7hq-7vfj"},{"url":"https://github.com/vercel/next.js/pull/96013"},{"url":"https://github.com/vercel/next.js/commit/019628571641dec57aaf349ba0c360e3964e6f12"},{"url":"https://github.com/vercel/next.js/releases/tag/v15.5.21"},{"url":"https://github.com/vercel/next.js/releases/tag/v16.2.11"},{"url":"https://github.com/advisories/GHSA-m99w-x7hq-7vfj"}],"tags":["ghsa","npm"],"ingestedAt":"2026-07-22T23:07:32.308Z","epss":0.01375,"epssPercentile":0.70399,"slug":"CVE-2026-64641","body":"## Overview\n\n## Impact\n\nCrafted requests targeting Next.js applications using App Router with at least one Server Action can lead to excessive CPU usage blocking processing of further requests in the same process.\n\n## Workarounds\n\nNo workaround exists besides upgrading. Applications using Pages Router or not using Server Actions are not vulnerable.\n\n## Affected packages\n\n- `next >= 13.0.0, < 15.5.21`\n- `next >= 16.0.0, < 16.2.11`\n\n## Remediation\n\nUpgrade to a patched release:\n\n- `next 15.5.21`\n- `next 16.2.11`","depth":"twilight","depthScore":42,"depthScoreParts":{"impact":41.3,"likelihood":0.3,"exploitation":0,"ransomware":0},"changes":[]}