CVE-2023-44270 is a medium-severity (CVSS 5.3) CWE-74 vulnerability in postcss. A fix is available for postcss — see the affected versions and patch details below.
PostCSS line return parsing error
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2023-44270.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
postcssnpmDescription
An issue was discovered in PostCSS before 8.4.31. It affects linters using PostCSS to parse external Cascading Style Sheets (CSS). There may be \r discrepancies, as demonstrated by @font-face{ font:(\r/*);} in a rule.
This vulnerability affects linters using PostCSS to parse external untrusted CSS. An attacker can prepare CSS in such a way that it will contains parts parsed by PostCSS as a CSS comment. After processing by PostCSS, it will be included in the PostCSS output in CSS nodes (rules, properties) despite being originally included in a comment.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | postcss | all versions | 8.4.31npm install postcss@8.4.31 |
Affected Products
postcsspostcssDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for postcss, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update postcss to 8.4.31 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-44270 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
Moderate impact. Red Hat products in the current affected scope that use the PostCSS component to parse external, untrusted CSS may allow an attacker to craft CSS comments that PostCSS incorrectly interprets as CSS nodes, causing commented content to be emitted as rules or properties. This may result in CSS injection…
There's no known mitigation for this issue. Red Hat recommends to not parse untrusted CSS input using PostCSS.Source: Red Hat security advisory for CVE-2023-44270 (CC BY 4.0)
| Product | Fixed in | Advisory |
|---|---|---|
| Discovery 1 for RHEL 9 | discovery/discovery-server-rhel9:1.12.0-1 | RHSA-2025:1249 |
| Red Hat OpenShift Container Platform 4.17 | openshift4/nmstate-console-plugin-rhel9:v4.17.0-202411261204.p0.gbc40e56.assembly.stream.el9 | RHSA-2024:10517 |
| Red Hat OpenShift Container Platform 4.17 | openshift4/ose-networking-console-plugin-rhel9:v4.17.0-202501150934.p0.g0244dff.assembly.stream.el9 | RHSA-2025:0654 |
| Red Hat OpenShift Container Platform 4.18 | openshift4/ingress-node-firewall-rhel9:v4.18.0-202501230001.p0.g1e43b4c.assembly.stream.el9 | RHSA-2024:6121 |
| Red Hat OpenShift Container Platform 4.18 | openshift4/aws-kms-encryption-provider-rhel9:v4.18.0-202501230001.p0.g088dcaf.assembly.stream.el9 | RHSA-2024:6122 |
| Red Hat OpenShift Dev Spaces 3 Containers | devspaces/code-rhel9:3.18-6 | RHSA-2025:0892 |
| Red Hat OpenShift GitOps 1.14 | openshift-gitops-1/argocd-rhel8:v1.14.3-4 | RHSA-2025:3069 |
| Red Hat OpenShift Service Mesh 2.5 for RHEL 8 | openshift-service-mesh/kiali-rhel8:1.73.17-1 | RHSA-2024:10908 |
Frequently Asked Questions
Is CVE-2023-44270 in your dependencies?
Find it across npm, including transitive dependencies.