What’s Vulnerable › Vulnerabilities

CVE-2026-93748: http-cache-semantics through 4.2.0 Cross-User Cache Disclosure via max-stale

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.6% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-18 · updated 2026-10-14
• Weakness: CWE-524

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.

Affected products

• kornelski http-cache-semantics: through 4.2.0

References

• 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/kornelski/http-cache-semantics/issues/56#issuecomment-5975759591

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