Description
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.
References8
- github.com/kornelski/http-cache-semantics
- github.com/kornelski/http-cache-semantics/blob/f01112e954b83cfa…
- github.com/kornelski/http-cache-semantics/blob/f01112e954b83cfa…
- github.com/kornelski/http-cache-semantics/issues/56
- www.vulncheck.com/advisories/http-cache-semantics-through-4.2.0…
- github.com/advisories/GHSA-ch52-4w7c-c8xp
- github.com/github/advisory-database/issues/10139
- github.com/kornelski/http-cache-semantics/issues/56#issuecommen…
Metrics
- CVSS 3.1
-
7.5
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - CVSS 4.0
-
8.7
HIGH
Score source: CNA
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 1% percentile: 49 · as of 8 November 2026
- CWE
- CWE-524
Could this be exploited in your environment?
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