Medium severity · published Sep 18, 2026
CVE-2026-93750
http-cache-semantics through 4.2.0 Cross-Client Cache Disclosure via Vary Wildcard
5.9
CVSS
0.4%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
High
Integrity
None
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 39% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
HT
http-cache-semantics · kornelski
through 4.2.0 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-93750
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-93750
github.com
https://github.com/kornelski/http-cache-semantics
github.com
https://github.com/kornelski/http-cache-semantics/blob/f01112e954b83cfa8765b633ba880e5e980aa54c/index.js#L483-L501
github.com
https://github.com/kornelski/http-cache-semantics/issues/57
www.vulncheck.com
https://www.vulncheck.com/advisories/http-cache-semantics-through-4.2.0-cross-client-cache-disclosure-via-vary-wildcard
More from http-cache-semantics
7.5
CVE-2026-93748
http-cache-semantics through 4.2.0 Cross-User Cache Disclosure via max-stale