CVE-2026-93750

MEDIUM 5.9

http-cache-semantics through 4.2.0 Cross-Client Cache Disclosure via Vary Wildcard

CVSS Score

5.9

EPSS Score

0.0%

EPSS Percentile

0th

http-cache-semantics through 4.2.0 contains a cache validation vulnerability in the _varyMatches() function that fails to properly validate Vary header wildcards due to byte-for-byte string comparison. Attackers can request URLs previously fetched by other clients to receive cached responses intended for different users, disclosing sensitive information across clients.

CWE	CWE-436
Vendor	kornelski
Product	http-cache-semantics
Published	Sep 18, 2026
Last Updated	Sep 18, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Attack Vector

Network

Attack Complexity

High

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

None

Availability

None

Affected Versions

kornelski / http-cache-semantics

0 ≤ 4.2.0

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/kornelski/http-cache-semantics/issues/57 github.com: https://github.com/kornelski/http-cache-semantics github.com: https://github.com/kornelski/http-cache-semantics/blob/f01112e954b83cfa8765b633ba880e5e980aa54c/index.js#L483-L501 vulncheck.com: https://www.vulncheck.com/advisories/http-cache-semantics-through-4.2.0-cross-client-cache-disclosure-via-vary-wildcard

Credits

🔍 Wayde Shi (PayPal Cyber Security Team)