How severe is CVE-2026-69153?

No CVSS score has been assigned to CVE-2026-69153 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-69153?

CVE-2026-69153 affects the following packages: postcss (npm). Ecosystems affected: npm.

How do I fix CVE-2026-69153?

Update postcss to 8.5.23 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-69153 is resolved across your whole dependency graph.

How do I detect CVE-2026-69153 in my npm dependencies?

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.

How do I mitigate CVE-2026-69153 if there is no patch (or I can't update yet)?

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.

How does O3 Security protect against CVE-2026-69153?

O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-69153 can be triaged on real exposure rather than presence alone.

Is CVE-2026-69153 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-69153 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-69153?

CVE-2026-69153 has an EPSS (Exploit Prediction Scoring System) score of 0.5%, placing it in the 38th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-69153?

CVE-2026-69153 is classified as Path Traversal (CWE-22), Information Exposure (CWE-200). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2026-69153 published, and has it been updated?

CVE-2026-69153 was published on August 3, 2026 and was last updated on September 5, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦 npm

Not in CISA KEV

CVE-2026-69153 — postcss

Fix: postcss/postcss@7beca13

CVE-2026-69153 is a Path Traversal vulnerability in postcss. A fix is available for postcss — see the affected versions and patch details below.

PostCSS: incomplete fix of CVE-2026-45623 — attacker-controlled sourceMappingURL reads arbitrary .map files when `from` is unset

Also known asGHSA-fxqj-rqcc-2cmp

Published

Aug 3, 2026

Updated

Sep 5, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Sep 17, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

Proof-of-concept exploit code exists

CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-69153.

EPSS Exploitation Probability

via FIRST.org ↗

0.5%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs38th percentile — riskier than 38% of all scored CVEsHighest risk

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Real-World Exposure

1 pkg affected

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.

16Kother npm packages depend on this — each one inherits the vulnerability until it's patched upstream

postcssnpm

258.3Mdownloads / week

Description

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 8.5.19, if from is unset, an attacker can cause PreviousMap.loadFile() to read an unintended source-map file by supplying an absolute or directory-traversal sourceMappingURL. The resulting map’s sources and sourcesContent may then be exposed to the application. This issue is fixed in version 8.5.19.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`postcss`	all versions	8.5.23`npm install postcss@8.5.23`

Detection & mitigation playbook

Open-source dependency

Detect
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 8.5.23 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-69153 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.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-69153 can be triaged on real exposure rather than presence alone.

Tailored to CVE-2026-69153. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

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.

Red HatModerate

Red Hat rates this flaw as Moderate because the information disclosed is limited to files with a .map extension. Source map files may contain source code paths and content, but the attacker cannot read arbitrary files on the system. Exploitation requires the application to process attacker-controlled CSS through…

Product	Fixed in	Advisory
Red Hat Enterprise Linux 10	`rh-podman-desktop-0:1.1.2-1.el10_2`	RHSA-2026:57590
RHEM 1.1 for RHEL 10	`flightctl-0:1.1.4-1.el10em`	RHSA-2026:68334
Streams for Apache Kafka 3.2.1	`postcss`	RHSA-2026:54435
multicluster engine for Kubernetes 2.11	`multicluster-engine/console-mce-rhel9:1786911977`	RHSA-2026:57194
multicluster engine for Kubernetes 2.17	`multicluster-engine/console-mce-rhel9:1786668856`	RHSA-2026:59593
multicluster engine for Kubernetes 2.6	`multicluster-engine/console-mce-rhel9:1787264250`	RHSA-2026:59579
multicluster engine for Kubernetes 2.8	`multicluster-engine/console-mce-rhel9:1787259048`	RHSA-2026:59558
multicluster engine for Kubernetes 2.9	`multicluster-engine/console-mce-rhel9:1787079359`	RHSA-2026:59559

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is CVE-2026-69153 in your dependencies?

O3 Security finds CVE-2026-69153 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

Scan my dependencies How O3 SCA works