Cache Validation Vulnerability in http-cache-semantics Affected by Kornelski
CVE-2026-93750

8.2HIGH

Key Information:

Vendor

Kornelski

Status
Http-cache-semantics
Vendor
CVE Published:
18 September 2026

What is CVE-2026-93750?

The http-cache-semantics library versions up to 4.2.0 contain a flaw in the _varyMatches() function. This vulnerability arises from improper validation of Vary header wildcards, enabling attackers to exploit byte-for-byte string comparison flaws. By manipulating requests, attackers can access cached responses meant for other users, potentially exposing sensitive data across different clients. This presents a substantial risk to the confidentiality of user information and necessitates immediate attention to mitigate the potential for exploitation.

Affected Version(s)

http-cache-semantics 0 <= 4.2.0

References

https://github.com/kornelski/http-cache-semantics/issues/57
issue-tracking
https://github.com/kornelski/http-cache-semantics
product
https://github.com/kornelski/http-cache-semantics/blob/f0...
technical-description

CVSS V4

Score:
8.2
Severity:
HIGH
Confidentiality:
High
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
High
Attack Required:
Physical
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Wayde Shi (PayPal Cyber Security Team)
.