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Fencer Vulns
medium 5.9

CVE-2026-93750 json

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

published 2026-09-18 51 d ago modified 2026-09-24 46 d ago also EUVD-2026-83255

cvss
5.9
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 38%
public exploits
0
none known

Summary

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.

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-93750 updated cvss 5.9

http-cache-semantics: http-cache-semantics: Information disclosure via improper Vary header wildcard validation

  • Red Hat Confidential Compute Attestation build-of-trustee/trustee-rhel9 Red Hat Exploit Intelligence exploit-intelligence/vulnerability-analysis-rhel9 Red Hat Gatekeeper 3 gatekeeper/gatekeeper-rhel9 Red Hat Migration Toolkit for Applications 8 mta/mta-cli-rhel9, mta/mta-nodejs-external-provider-rhel9, mta/mta-generic-external-provider-rhel9 Red Hat Migration Toolkit for Containers rhmtc/openshift-migration-ui-rhel8 Red Hat Multicluster Engine for Kubernetes multicluster-engine/console-mce-rhel9
    +12 more products
    Red Hat Advanced Cluster Management for Kubernetes 2 rhacm2/console-rhel9 Red Hat AMQ Broker 7 amq-broker-bin.zip, amq-broker-maven-repository.zip Red Hat build of Apache Camel - HawtIO 4 rhaf-hawtio-maven-repository.zip Red Hat build of Apache Camel for Spring Boot 4 rhaf-camel-maven-repository.zip, rhaf-camel-spring-boot-maven-repository.zip, rhaf-camel-for-springboot-maven-repository.zip Red Hat Build of Podman Desktop rh-podman-desktop Red Hat Connectivity Link 1 rhcl-1/rhcl-console-plugin-rhel9 Red Hat Developer Hub 1 rhdh/rhdh-hub-rhel9, rhdh/red-hat-developer-hub-backstage-plugin-lightspeed-backend, rhdh/red-hat-developer-hub-backstage-plugin-orchestrator-backend Red Hat Enterprise Linux 8 npm, dotnet, nodejs, grafana, dotnet9.0, dotnet-host, +37 more Red Hat Enterprise Linux 9 npm, nodejs, grafana, sgx-mpa, tdx-qgs, sgx-libs, +29 more Red Hat Enterprise Linux 10 grafana, nodejs22, nodejs24, nodejs26, dotnet9.0, linux-sgx, +6 more Red Hat Enterprise Linux AI (RHEL AI) 3 rhelai3/bootc-cuda-rhel9, rhelai3/bootc-rocm-rhel9, rhelai3/bootc-gaudi-rhel9, rhelai3/disk-image-cuda-rhel9 Red Hat Fuse 7 http-cache-semantics
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Hardened Images grafana13.2 13.2.1-0.5.hum1
    affected: workaround, no fix available
  • Red Hat JBoss Enterprise Application Platform 7 jboss-eap-patch.zip, jboss-eap-maven-repository.zip, jboss-eap-full-maven-repository.zip, jboss-eap-runtime-maven-repository.zip, jboss-eap-incremental-maven-repository.zip Red Hat OpenShift AI (RHOAI) rhoai/odh-mlflow-rhel9, rhoai/odh-core-bff-rhel9, rhoai/odh-dashboard-rhel9, rhoai/odh-mod-arch-maas-rhel9, rhoai/odh-feature-server-rhel9, rhoai/odh-mod-arch-automl-rhel9, +7 more Red Hat OpenShift Container Platform 4 openshift4/ose-console, openshift4/ose-console-rhel9, openshift4/ose-agent-installer-ui-rhel9 Red Hat OpenShift Container Platform 5 openshift5/ose-console-rhel9, openshift5/ose-agent-installer-ui-rhel9 Red Hat Openshift Data Foundation 4 odf4/mcg-core-rhel9, odf4/odf-console-rhel9, odf4/ocs-client-console-rhel9, odf4/odf-multicluster-console-rhel9 Red Hat OpenShift Dev Spaces devspaces/udi-rhel9, devspaces/openvsx-rhel9, devspaces/dashboard-rhel9, devspaces/pluginregistry-rhel9
    +3 more products
    Red Hat Satellite 6 satellite/iop-remediations-rhel9 Red Hat Single Sign-On 7 rh-sso-server-dist.zip Red Hat Self-service automation portal 2 ansible-automation-platform/automation-portal, ansible-automation-platform/bootc-automation-portal-rhel9
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Hardened Images dotnet9.0, dotnet10.0 10.0.112-1.hum1, dotnet8.0 8.0.130-0.1.hum1, grafana13.1 13.1.6-0.2.hum1, grafana12.4 12.4.10-0.6.hum1
    not affected: component not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
51 d ago

Exploit prediction

0.45% chance of exploitation in the next 30 days, higher than 38% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/kornelski/http-cache-semantics/issues/57 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 8.2 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
CNA 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
CNA 4.0 8.2 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
NVD 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected products

  • kornelski http-cache-semantics

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.