7.5

CVE-2026-73646: PostCSS: Path Traversal in Previous Source Map Auto-Loading (sourceMappingURL) leads to Arbitrary .map File Disclosure

Awaiting analysis
AliasesUBUNTU-CVE-2026-73646DEBIAN-CVE-2026-73646CGA-282m-c8r7-mqqv
Published 17-08-2026Last modified 17-08-2026

Vulnerability summary

CVE-2026-73646 is a high (CVSS 7.5) vulnerability in postcss. EPSS estimates a 0.53% chance of exploitation in the next 30 days, higher than 44.8% of scored vulnerabilities.

Priority
Prioritisesevere

Severe, CVSS 7.5 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 1% (FIRST, 03-11-2026)

Source freshness unavailable

How is this decided?
CVSS score
7.5/10
010
High · v3.1 (CVE.org)
EPSS score
0.53%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 3 · Related 2
OPENSUSE-SU-2026:12070-1RHSA-2026:50287RHSA-2026:54520CGA-HQ4J-XP9C-RHJ6

Timeline

  1. 17-08-2026
    PublishedVulnerability first disclosed.
  2. 17-08-2026
    Last modifiedVulnerability information updated.

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 8.5.18, 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.

CVSS metrics

7 scores · 7 sources · 1 version

EPSS trend

Probability

0.53%

Chance of exploitation in the next 30 days

Percentile

45%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.53% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Chainguard63 products
  • airflow-2All versions (No fix recorded)
  • airflow-core-2All versions (No fix recorded)
  • arangodb-3.11< 3.11.14.5-r1
  • arangodb-3.12< 3.12.9.4-r22
  • authentik-2025.12< 2025.12.6-r6
Wolfi9 products
  • jitsucom-jitsu-console< 2.11.0-r30
  • jupyter-base-notebook< 7.6.3-r2
  • langfuse-3-compat< 3.225.7-r6
  • langfuse-3-worker< 3.224.3-r0
  • nextcloud-server-32< 32.0.13-r2
Debian1 product
  • node-postcssAll versions (No fix recorded) | < 8.5.19+~cs10.2.23-1
Npm1 product
  • postcss< 8.5.18
Postcss1 product
Ubuntu1 product
  • node-postcssAll versions (No fix recorded)

6 vendors · 76 products

References

9 links