CVE-2026-84933
published 2026-09-04CVE-2026-84933: undici's cache interceptor does not handle the Set-Cookie response header anywhere in its cache path, so it neither refuses to store nor strips that header. In…
PriorityP348high8.2CVSS 3.1
AVNACLPRNUINSUCHILAN
EPSS
0.30%
22.8th percentile
undici's cache interceptor does not handle the Set-Cookie response header anywhere in its cache path, so it neither refuses to store nor strips that header. In shared cache mode, which is the default, an otherwise cacheable response that carries a Set-Cookie header, for example one marked with a public and max-age directive, is stored and then re-served to a later caller that matches the same cache key. As a result one caller's cookie is disclosed to a different caller, and an untrusted server can inject cookies into cached responses served to all subsequent callers. This violates the requirement that a shared cache must not store cookies. This affects undici versions from 7.0.0 up to 7.29.1 and from 8.0.0 up to 8.10.2. Users should upgrade to undici 7.29.1 or 8.10.2.
Affected
51 ranges· showing 25
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| ansible-automation-platform | automation-portal | — | — |
| ansible-automation-platform | bootc-automation-portal-rhel9 | — | — |
| devspaces | code-rhel9 | — | — |
| devspaces | dashboard-rhel9 | — | — |
| devspaces | openvsx-rhel9 | — | — |
| devspaces | pluginregistry-rhel9 | — | — |
| exploit-intelligence | vulnerability-analysis-rhel9 | — | — |
| external-secrets-management | console-plugin-rhel9 | — | — |
| grafana | grafana | — | — |
| nodejs | undici | >= 7.0.0 < 7.29.1 | 7.29.1 |
| nodejs | undici | >= 8.0.0 < 8.10.2 | 8.10.2 |
| nodejs_22 | nodejs | — | — |
| nodejs_24 | nodejs | — | — |
| nodejs_26 | nodejs | — | — |
| odf4 | mcg-core-rhel9 | — | — |
| odf4 | ocs-client-console-rhel9 | — | — |
| odf4 | odf-console-rhel9 | — | — |
| odf4 | odf-multicluster-console-rhel9 | — | — |
| openshift-pipelines | pipelines-console-plugin-pf5-rhel9 | — | — |
| openshift-pipelines | pipelines-console-plugin-rhel9 | — | — |
| openshift4 | ose-monitoring-plugin-rhel9 | — | — |
| rhdh | red-hat-developer-hub-backstage-plugin-lightspeed-backend | — | — |
| rhdh | red-hat-developer-hub-backstage-plugin-orchestrator-backend | — | — |
| rhdh | red-hat-developer-hub-backstage-plugin-orchestrator-backend-module-loki | — | — |
| rhdh | red-hat-developer-hub-backstage-plugin-scaffolder-backend-module-orchestrator | — | — |
CVSS provenance
nvdv3.18.2HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
vendor_redhat6.5MEDIUM
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GHSA
undici vulnerable to cross-user cookie disclosure via Set-Cookie caching in shared caches
ghsa·2026-09-29
CVE-2026-84933 [MEDIUM] CWE-200 undici vulnerable to cross-user cookie disclosure via Set-Cookie caching in shared caches
undici vulnerable to cross-user cookie disclosure via Set-Cookie caching in shared caches
### Impact
undici's `interceptors.cache()` does not handle `Set-Cookie` in the cache path. In shared-cache mode (`type: 'shared'`, the default), a cacheable response (for example `Cache-Control: public, max-age=...`) carrying a `Set-Cookie` header is stored, and the stored `Set-Cookie` is re-served to a later caller that hits the same cache key. This exposes one user's cookie to another caller and lets an untrusted upstream inject cookies into cached responses served to all subsequent callers, violating RFC 6265 section 7.2 (a shared cache must not store cookies). Applications using the shared cache interceptor against untrusted or multi-user upstreams are affected. Private caches (`type: 'private'`
VulDB
undici prior 7.29.1/8.10.2 Cache Interceptor information disclosure (EUVD-2026-71518)
vuldb·2026-09-15·CVSS 8.2
CVE-2026-84933 [HIGH] undici prior 7.29.1/8.10.2 Cache Interceptor information disclosure (EUVD-2026-71518)
A vulnerability identified as problematic has been detected in undici. Affected is an unknown function of the component Cache Interceptor. This manipulation causes information disclosure.
The identification of this vulnerability is CVE-2026-84933. It is possible to initiate the attack remotely. There is no exploit available.
You should upgrade the affected component.
Red Hat
undici: undici: Cross-user cookie disclosure via Set-Cookie caching
vendor_redhat·2026-09-04·CVSS 6.5
CVE-2026-84933 [MEDIUM] CWE-524 undici: undici: Cross-user cookie disclosure via Set-Cookie caching
undici: undici: Cross-user cookie disclosure via Set-Cookie caching
A flaw was found in undici. The software's caching mechanism, when operating in shared cache mode, improperly stores responses that include 'Set-Cookie' headers. This oversight allows an untrusted server to inject cookies into cached responses. Consequently, sensitive cookie information from one user can be inadvertently disclosed to another user accessing the same cached content.
Package: exploit-intelligence/vulnerability-analysis-rhel9 (Exploit Intelligence) - Out of support scope
Package: openshift-pipelines/pipelines-console-plugin-pf5-rhel9 (OpenShift Pipelines) - Fix deferred
Package: openshift-pipelines/pipelines-console-plugin-rhel9 (OpenShift Pipelines) - Fix deferred
Package: amq-broker-bin.zip (Red Hat AMQ
No detection rules found.
No public exploits indexed.
Bugzilla
CVE-2026-84933 nodejs24: undici: Cross-user cookie disclosure via Set-Cookie caching [fedora-all]
bugzilla·2026-09-11·CVSS 6.5
CVE-2026-84933 [MEDIUM] CVE-2026-84933 nodejs24: undici: Cross-user cookie disclosure via Set-Cookie caching [fedora-all]
CVE-2026-84933 nodejs24: undici: Cross-user cookie disclosure via Set-Cookie caching [fedora-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
undici's cache interceptor does not handle the Set-Cookie response header anywhere in its cache path, so it neither refuses to store nor strips that header. In shared cache mode, which is the default, an otherwise cacheable response that carries a Set-Cookie header, for example one marked with a public and max-age directive, is stored and then re-served to a later caller that matches the same cache key. As a result one caller's cookie is disclosed to a different caller, a
Bugzilla
CVE-2026-84933 undici: undici: Cross-user cookie disclosure via Set-Cookie caching
bugzilla·2026-09-04·CVSS 6.5
CVE-2026-84933 [MEDIUM] CVE-2026-84933 undici: undici: Cross-user cookie disclosure via Set-Cookie caching
CVE-2026-84933 undici: undici: Cross-user cookie disclosure via Set-Cookie caching
undici's cache interceptor does not handle the Set-Cookie response header anywhere in its cache path, so it neither refuses to store nor strips that header. In shared cache mode, which is the default, an otherwise cacheable response that carries a Set-Cookie header, for example one marked with a public and max-age directive, is stored and then re-served to a later caller that matches the same cache key. As a result one caller's cookie is disclosed to a different caller, and an untrusted server can inject cookies into cached responses served to all subsequent callers. This violates the requirement that a shared cache must not store cookies. This affects undici versions from 7.0.0 up to 7.29.1 and from 8.0.0
2026-09-04
Published