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Fencer Intel
high 7.5

CVE-2026-73646 json

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

published 3mo ago modified last mo. also EUVD-2026-60239 , GHSA-r28c-9q8g-f849

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
  • postcss 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

Is CVE-2026-73646 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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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
2mo ago

Exploit prediction

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

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 Intel 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.

The maintainers of postcss/postcss published their own advisory on GitHub. Reviewed sources take precedence over it.

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