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Fencer Vulns
high 7.5

CVE-2026-73646 json

PostCSS: Path Traversal in Previous Source Map Auto-Loading (sourceMappingURL) leads to Arbitrary .map File Disclosure

published 2026-07-24 3 mo ago modified 2026-09-18 51 d ago also GHSA-r28c-9q8g-f849 , EUVD-2026-60239

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 45%
public exploits
0
none known

Summary

PostCSS takes a CSS file and provides an API to analyze and modify its rules by transforming the rules into an Abstract Syntax Tree. Prior to 8.5.18, lib/previous-map.js loadMap() passes attacker-controlled sourceMappingURL values to join(dirname(opts.from), annotation), and loadFile() permits traversed or absolute .map paths, allowing untrusted CSS processed without map: false to disclose sourcesContent from arbitrary reachable .map files through result.map. This issue is fixed in version 8.5.18.

Patch / fix

  • npm postcss 8.5.18
  • node-postcss Debian 14 8.5.19+~cs10.2.23-1

debian advisories DEBIAN-CVE-2026-73646

  • prometheus3.5 hummingbird 1 3.5.5-0.8.hum1
  • prometheus3.13 hummingbird 1 3.13.2-0.2.hum1

red hat advisories RHSA-2026:54520RHSA-2026:50287

  • velociraptor openSUSE Tumbleweed 0.76.7.0.git145.b60ef1146-1.1

opensuse advisories openSUSE-SU-2026:12070-1

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-2026-73646 updated cvss 7.5

postcss: PostCSS: Information disclosure via path traversal in source map auto-loading

  • Red Hat Node HealthCheck Operator workload-availability/node-remediation-console-rhel8, workload-availability/node-healthcheck-rhel9-operator, workload-availability/node-healthcheck-operator-bundle, workload-availability/node-healthcheck-must-gather-rhel9 Red Hat OpenShift Pipelines openshift-pipelines/pipelines-hub-ui-rhel8, openshift-pipelines/pipelines-hub-ui-rhel9
    affected: no fix available
  • Red Hat Ansible Automation Platform 2 automation-controller 4.5.35-1.el9ap
    affected: no fix planned “Will not fix”
  • Red Hat build of Apicurio Registry 3 apicurio/apicurio-registry-ui-rhel8 Red Hat Build of Podman Desktop rh-podman-desktop.git 1.0.0 Red Hat Ceph Storage 4 rhceph/rhceph-4-dashboard-rhel8 Red Hat Enterprise Linux 9 grafana-pcp, grafana-pcp 6.1.0-1.el10 Red Hat Enterprise Linux 10 grafana-pcp 6.1.0-1.el10, rh-podman-desktop 1.1.2-1.el10_2
    affected: no fix available
  • 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
    affected: no fix available, no fix planned “Will not fix”
  • Red Hat Fuse 7 postcss 7.0.14 Red Hat JBoss Enterprise Application Platform 7 jboss-eap-patch.zip 7.4.23, jboss-eap-maven-repository.zip 7.4.23, jboss-eap-runtime-maven-repository.zip 7.4.24, jboss-eap-full-maven-repository.zip 7.4.22.GA-CR1, jboss-eap-incremental-maven-repository.zip 7.4.23
    affected: no fix planned “Will not fix”
  • Red Hat OpenShift AI (RHOAI) rhoai/odh-mlflow-rhel9 Red Hat Openshift Data Foundation 4 odf4/odf-console-rhel9, odf4/ocs-client-console-rhel9, odf4/odf-multicluster-console-rhel9 Red Hat OpenShift Dev Spaces devspaces/code-rhel9
    affected: no fix available
  • Red Hat OpenShift GitOps microshift-gitops 1.19.2-36.el9 Red Hat Single Sign-On 7 postcss 7.0.14 Red Hat Secrets Management Console for Red Hat OpenShift external-secrets-management/console-plugin-rhel9
    affected: no fix planned “Will not fix”
  • Red Hat Advanced Cluster Management for Kubernetes 2.11 rhacm2/console-rhel9 1788880484
    fixed: vendor fix RHSA-2026:67538
show 16 more
  • Red Hat Advanced Cluster Management for Kubernetes 2.13 rhacm2/console-rhel9 1788972841
    fixed: vendor fix RHSA-2026:67540
  • Red Hat Hardened Images prometheus3.5 3.5.5-0.8.hum1, prometheus3.13 3.13.2-0.2.hum1
    fixed: vendor fix RHSA-2026:50287
  • Red Hat Migration Toolkit 1.8 rhmtc/openshift-migration-ui-rhel8 1789546373
    fixed: vendor fix RHSA-2026:68681
  • Red Hat OpenShift AI 2.25 rhoai/odh-feature-server-rhel9 1792148523
    fixed: vendor fix RHSA-2026:87410
  • Red Hat OpenShift AI 3.4 rhoai/odh-feature-server-rhel9 1791863220
    fixed: vendor fix RHSA-2026:84734
  • Red Hat OpenShift AI 3.5 rhoai/odh-workbench-codeserver-datascience-cpu-py312-rhel9 1791825469
    fixed: vendor fix RHSA-2026:86891
  • Red Hat OpenShift Dev Spaces 3.30 devspaces/openvsx-rhel9 1787759145, devspaces/dashboard-rhel9 1789162884
    fixed: vendor fix RHSA-2026:68754
  • Red Hat Satellite 6.18 satellite/iop-vulnerability-frontend-rhel9 1789660969, satellite/iop-host-inventory-frontend-rhel9 1789613107
    fixed: vendor fix RHSA-2026:68756
  • Red Hat Satellite 6.19 satellite/iop-advisor-frontend-rhel9 1789659565, satellite/iop-vulnerability-frontend-rhel9 1789660983, satellite/iop-host-inventory-frontend-rhel9 1789624519
    fixed: vendor fix RHSA-2026:68748
  • Red Hat Trusted Artifact Signer 1.3 rhtas/rekor-search-ui-rhel9 1789725818
    fixed: vendor fix RHSA-2026:70829
  • Red Hat Trusted Artifact Signer 1.4 rhtas/rekor-search-ui-rhel9 1791534339
    fixed: vendor fix RHSA-2026:83598
  • Red Hat Cost Management On Premise costmanagement/costmanagement-ui-rhel10
    not affected: vulnerable code not present
  • Red Hat Gatekeeper 3 gatekeeper/gatekeeper-rhel9
    not affected: vulnerable code not in execute path
  • Red Hat Multicluster Engine for Kubernetes multicluster-engine/console-mce-rhel9 Red Hat OpenShift Lightspeed openshift-lightspeed/lightspeed-console-plugin-rhel9, openshift-lightspeed/lightspeed-agentic-console-rhel9, openshift-lightspeed/lightspeed-console-plugin-419-rhel9, openshift-lightspeed/lightspeed-console-plugin-pf5-rhel9 Red Hat OpenShift Pipelines openshift-pipelines/pipelines-console-plugin-rhel9, openshift-pipelines/pipelines-console-plugin-pf5-rhel9
    not affected: vulnerable code not present
  • Red Hat OpenShift Service Mesh 3 openshift-service-mesh/kiali-rhel9-operator, openshift-service-mesh/kiali-operator-bundle
    not affected: component not present
  • Red Hat 3scale API Management Platform 2 3scale-amp2/system-rhel8 Red Hat Advanced Cluster Management for Kubernetes 2 rhacm2/volsync-rhel9, rhacm2/volsync-operator-bundle Red Hat Advanced Cluster Management for Kubernetes 2.11 rhacm2/thanos-rhel9 1788558581, rhacm2/prometheus-rhel9 1788951176, rhacm2/acm-grafana-rhel9 1788559869, rhacm2/acm-search-v2-rhel9 1788987820, rhacm2/node-exporter-rhel9 1788880100, rhacm2/observatorium-rhel9 1788558516, +34 more Red Hat Advanced Cluster Management for Kubernetes 2.13 rhacm2/thanos-rhel9 1789136147, rhacm2/acm-cli-rhel9 1788560311, rhacm2/prometheus-rhel9 1788952534, rhacm2/acm-grafana-rhel9 1788954486, rhacm2/acm-search-v2-rhel9 1788987824, rhacm2/node-exporter-rhel9 1788945205, +37 more Red Hat AMQ Broker 7 amq-broker-bin.zip 7.14.1.CR2, amq-broker-maven-repository.zip 7.14.1.CR3
    not affected: vulnerable code not present

33 more not affected in the full advisory

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
yes
Technical impact
partial
Assessed
2 mo ago

Exploit prediction

0.53% chance of exploitation in the next 30 days, higher than 45% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/postcss/postcss/security/advisories/GHSA-r28c-9q8g-f849 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
GitHub 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected packages

ecosystem package affected fixed in
npm postcss
<8.5.18
8.5.18

Affected products

  • postcss postcss

Classification

Weakness
  • CWE-22 Improper Limitation of a Pathname to a Restricted Directory

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.