http-cache-semantics through 4.2.0 Cross-Client Cache Disclosure via Vary Wildcard
Summary
| CVE | CVE-2026-93750 |
|---|---|
| State | PUBLISHED |
| Assigner | VulnCheck |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-18 18:18:33 UTC |
| Updated | 2026-09-23 17:17:49 UTC |
| 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. |
Risk And Classification
Primary CVSS: v4.0 8.2 HIGH from [email protected]
CVSS:4.0/AV:N/AC:H/AT:P/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: 0.003500000 probability, percentile 0.286670000 (date 2026-09-23)
Problem Types: CWE-436 | CWE-436 Interpretation Conflict
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 8.2 | HIGH | CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/C... |
| 4.0 | CNA | CVSS | 8.2 | HIGH | CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N |
| 3.1 | [email protected] | Primary | 5.9 | MEDIUM | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N |
| 3.1 | CNA | CVSS | 5.9 | MEDIUM | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N |
CVSS v4.0 Breakdown
Attack Vector
NetworkAttack Complexity
HighAttack Requirements
PresentPrivileges Required
NoneUser Interaction
NoneConfidentiality
HighIntegrity
NoneAvailability
NoneSub Conf.
NoneSub Integrity
NoneSub Availability
NoneCVSS:4.0/AV:N/AC:H/AT:P/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
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
HighPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
HighIntegrity
NoneAvailability
NoneCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Kornelski | Http-cache-semantics | affected 4.2.0 semver | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/kornelski/http-cache-semantics/issues/57 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | github.com | |
| www.vulncheck.com/advisories/http-cache-semantics-through-4.2.0-cross-client-ca... | [email protected] | www.vulncheck.com | |
| github.com/kornelski/http-cache-semantics/blob/f01112e954b83cfa8765b633b... | [email protected] | github.com | |
| github.com/kornelski/http-cache-semantics | [email protected] | github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Wayde Shi (PayPal Cyber Security Team) (en)
There are currently no legacy QID mappings associated with this CVE.