CVE-2026-93748

http-cache-semantics through 4.2.0 fails to properly validate security-zeroed cache entries when processing client max-stale directives, allowing unauthenticated attackers to retrieve cached responses belonging to other users. Attackers can request the same URL with a large max-stale value to obtain another user's Set-Cookie session credentials from shared-cache entries that were deliberately zeroed for security reasons.

• https://github.com/kornelski/http-cache-semantics
• https://github.com/kornelski/http-cache-semantics/blob/f01112e954b83cfa8765b633ba880e5e980aa54c/index.js#L425-L441
• https://github.com/kornelski/http-cache-semantics/blob/f01112e954b83cfa8765b633ba880e5e980aa54c/index.js#L603-L623
• https://github.com/kornelski/http-cache-semantics/issues/56
• https://www.vulncheck.com/advisories/http-cache-semantics-through-4.2.0-cross-user-cache-disclosure-via-max-stale
• https://github.com/advisories/GHSA-ch52-4w7c-c8xp
• https://github.com/github/advisory-database/issues/10139
• https://github.com/kornelski/http-cache-semantics/issues/56#issuecomment-5975759591