{"id":"CVE-2026-14643","aliases":["GHSA-jr45-8vmc-qm54"],"title":"undici vulnerable to cross-user information disclosure via whitespace around equals in Cache-Control directives","summary":"undici vulnerable to cross-user information disclosure via whitespace around equals in Cache-Control directives","severity":"medium","cvss":5.9,"cwe":["CWE-436","CWE-524"],"vendor":"undici","product":"undici","ecosystem":"npm","affected":["undici >= 7.0.0, < 7.29.0","undici >= 8.0.0, < 8.9.0"],"patched":["undici 7.29.0","undici 8.9.0"],"published":"2026-08-03","updated":"2026-08-03","source":"GHSA","sourceUrl":"https://github.com/advisories/GHSA-jr45-8vmc-qm54","references":[{"url":"https://github.com/nodejs/undici/security/advisories/GHSA-jr45-8vmc-qm54"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-14643"},{"url":"https://github.com/nodejs/undici/commit/85a240551c9feb8b8a0ecc56c84b2b3015add8a9"},{"url":"https://github.com/nodejs/undici/commit/cb105d7c79069150982fa11acada0dd94a60dbbc"},{"url":"https://cna.openjsf.org/security-advisories.html"},{"url":"https://github.com/nodejs/undici/releases/tag/v7.29.0"},{"url":"https://github.com/nodejs/undici/releases/tag/v8.9.0"},{"url":"https://github.com/advisories/GHSA-jr45-8vmc-qm54"}],"tags":["ghsa","npm"],"epss":0.00304,"epssPercentile":0.23335,"ingestedAt":"2026-08-03T20:29:32.476Z","slug":"CVE-2026-14643","body":"## Overview\n\n## Impact\n\nUndici's cache interceptor mishandles optional whitespace (OWS) placed around the `=` of a qualified `no-cache` or `private` Cache-Control directive, such as `no-cache =\"authorization\"` (OWS before `=`) or `no-cache= \"authorization\"` (OWS after `=`). The parser either drops the directive entirely or stores a field name with literal quote characters, so the downstream cache decisions do not recognize the qualification and the response is stored.\n\nIn shared-cache mode, this allows a response containing one user's authenticated data to be served from cache to a subsequent caller, including an unauthenticated caller, when both requests resolve to the same cache key. The impact class is identical to CVE-2026-9678 (GHSA-pr7r-676h-xcf6); this advisory covers the whitespace-around-`=` bypass that the earlier fix did not normalize.\n\nAffected applications are those that explicitly enable the cache interceptor (`interceptors.cache()`) in shared mode, forward `Authorization` headers upstream, and receive cacheable responses with qualified `private` or `no-cache` directives whose field-name list is padded with OWS around the `=`.\n\n## Patches\n\nUpgrade to undici v7.29.0 or v8.9.0.\n\n## Workarounds\n\nIf upgrade is not immediately possible, disable shared-cache mode for traffic that includes `Authorization` headers, avoid caching responses to authenticated requests, or add `Vary: Authorization` upstream.\n\n## Affected packages\n\n- `undici >= 7.0.0, < 7.29.0`\n- `undici >= 8.0.0, < 8.9.0`\n\n## Remediation\n\nUpgrade to a patched release:\n\n- `undici 7.29.0`\n- `undici 8.9.0`","depth":"sunlit","depthScore":33,"depthScoreParts":{"impact":32.5,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}