CVE-2026-45623

CRITICALNVD 9.19.1—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.1 under NVD CVSS v3. EPSS exploit probability: 0.6% (47th percentile of EPSS-scored CVEs). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
Trending — Patch released this week
9.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.6%CVSS: 9.1Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

PostCSS takes a CSS file and provides an API to analyze and modify its rules by transforming the rules into an Abstract Syntax Tree. In versions 8.5.11 and prior, the PreviousMap parses the /*# sourceMappingURL=PATH */ comment from any CSS string passed to process() and dereferences PATH against the local filesystem with no scheme, allowlist, or traversal check. An attacker who controls the CSS input can cause the host process to read any file readable by Node and leak the first ~10 bytes of its content through the resulting JSON.parse SyntaxError message. The bug also yields a precise file-existence oracle and a controllable-read primitive that may be combined with large-file targets for DoS. The behaviour is triggered with PostCSS's default options — no from, no map, no plugins required — and is therefore reachable from any pipeline that runs untrusted CSS through PostCSS (CMS themes, user-uploaded styles, browser-extension/userstyle processors, build pipelines for third-party packages, blog comment renderers, etc.). This issue has been fixed in version 8.5.12.

CVSS v3
9.1
EG Score
9.1CRITICALmedium confidence
EG Risk
46
EG Risk 46/100CISA SSVC

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity91% × 45%
Exploitation1% × 40%
Automatability30% × 15%
CISA SSVC: Track at low or medium mission impact; Track* or Attend at high (mission-essential systems).
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
0.6%
EPSS %ILE
47th
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Track* or Attend at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation none (no KEV listing, exploit record or EPSS ≥ 50%) · Automatable unknown (not published for this CVE) · Technical impact total (CVSS ≥ 9.0). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

July 23, 2026

Last Modified

August 7, 2026

Advisory Details (1)

Auto-updated Sep 16, 2026
🔬 Proof of concept available. Patch available. Sources: github.
github Patch Available🟡 PoC Available

Arbitrary file read and information disclosure via attacker-controlled sourceMappingURL in CSS comments · Advisory · postcss/postcss · GitHub

https://github.com/postcss/postcss/security/advisories/GHSA-6g55-p6wh-862q

Vendor Advisories for CVE-2026-45623(20)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(30)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatopenshift4/ose-console-rhel9:17899395652026-10-01redhat
redhatforeman-0:3.18.0.14-1.el9sat2026-10-01redhat
redhatsatellite/iop-advisor-frontend-rhel9:17906933532026-10-01redhat
redhatcluster-observability-operator/prometheus-rhel9:17908579222026-10-01redhat
redhatopenshift4/ose-console:17893320712026-09-24redhat
redhatopenshift4/ose-console-rhel9:17894537272026-09-24redhat
redhatopenshift4/ose-console:17893692992026-09-24redhat
redhatdevspaces/dashboard-rhel9:17891628842026-09-17redhat
redhatopenshift4/ose-console-rhel9:17888059262026-09-17redhat
redhatsatellite/iop-vulnerability-frontend-rhel9:17896609832026-09-17redhat
redhatopenshift4/ose-console-rhel9:17883115202026-09-09redhat
redhatopenshift4/ose-console-rhel9:17883509632026-09-08redhat
redhatopenshift4/ose-console-rhel9:17883599342026-09-08redhat
redhatrhoai/odh-mod-arch-model-registry-rhel9:17883121572026-09-08redhat
redhatsatellite/iop-host-inventory-frontend-rhel9:17883222432026-09-03redhat
redhatsatellite/iop-host-inventory-frontend-rhel9:17882609412026-09-03redhat
redhatopenshift4/ose-console-rhel9:17877463822026-09-01redhat
redhatdevspaces/openvsx-rhel9:17877591452026-09-01redhat
redhatdiscovery/discovery-ui-rhel9:17882061962026-08-31redhat
redhatrhoai/odh-mod-arch-model-registry-rhel9:17872506172026-08-27redhat
redhatrhacm2/console-rhel9:17873351052026-08-26redhat
redhatrhacm2/console-rhel9:17876870622026-08-26redhat
redhatrhacm2/console-rhel9:17873392482026-08-26redhat
redhatrhacm2/console-rhel9:17873392492026-08-26redhat
redhatmulticluster-engine/console-mce-rhel9:17872590482026-08-25redhat
redhatopenshift-service-mesh/kiali-rhel9:17871656832026-08-25redhat
redhatmulticluster-engine/console-mce-rhel9:17870793592026-08-25redhat
redhatopenshift-service-mesh/kiali-rhel9:17870764952026-08-25redhat
redhatopenshift-service-mesh/kiali-rhel9:17870921982026-08-25redhat
redhatmulticluster-engine/console-mce-rhel9:17866688562026-08-25redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(5 across 5 ecosystems)
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
node-postcss8.2.1+~cs5.3.23-8 ... 8.5.9+~cs9.3.30-1 (31 versions)
  • every version on: no fix on record
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
node-postcss8.4.20+~cs8.0.23-1 ... 8.5.9+~cs9.3.30-1 (19 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
node-postcss8.4.49+~cs9.2.32-1 ... 8.5.9+~cs9.3.30-1 (15 versions)
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
node-postcss8.4.49+~cs9.2.32-1, 8.5.6+~cs9.3.28-1, 8.5.8+~cs9.3.30-1, 8.5.9+~cs9.3.30-1
  • every version up to 8.5.12+~cs9.3.32-1: fixed in 8.5.12+~cs9.3.32-1
—
npm(1)
PackageVulnerable rangeFix by version rangeDependents
postcss—
  • every version up to 8.5.12: fixed in 8.5.12
—

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Additional Vendor Advisories

(17)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 14× in last 7d / 96× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 263 total refreshes for this CVE.

  1. 2026-10-04 23:22 UTCEPSS rescore
  2. 2026-10-04 12:43 UTCVendor advisory
  3. 2026-10-04 08:21 UTCEG score recompute
  4. 2026-10-04 08:21 UTCVendor advisory
  5. 2026-10-03 14:25 UTCEPSS rescore
  6. 2026-10-03 03:24 UTCEG score recompute
  7. 2026-10-03 03:24 UTCVendor advisory
  8. 2026-10-01 19:50 UTCEPSS rescore
  9. 2026-10-01 14:28 UTCVendor advisory
  10. 2026-10-01 10:22 UTCVendor advisory
  11. 2026-10-01 06:17 UTCEG score recompute
  12. 2026-10-01 06:17 UTCVendor advisory
  13. 2026-09-30 15:03 UTCEPSS rescore
  14. 2026-09-28 13:17 UTCVendor advisory
  15. 2026-09-28 09:11 UTCVendor advisory
  16. 2026-09-28 05:06 UTCEG score recompute
  17. 2026-09-28 05:06 UTCVendor advisory
  18. 2026-09-27 13:48 UTCEPSS rescore
  19. 2026-09-26 15:58 UTCEPSS rescore
  20. 2026-09-24 11:01 UTCVendor advisory
  21. 2026-09-24 06:35 UTCVendor advisory
  22. 2026-09-24 02:29 UTCVendor advisory
  23. 2026-09-23 22:21 UTCEG score recompute
  24. 2026-09-23 22:21 UTCVendor advisory
  25. 2026-09-23 17:53 UTCEPSS rescore
Show 75 more
  1. 2026-09-23 11:03 UTCVendor advisory
  2. 2026-09-23 06:56 UTCVendor advisory
  3. 2026-09-23 02:51 UTCVendor advisory
  4. 2026-09-22 22:43 UTCEG score recompute
  5. 2026-09-22 22:43 UTCVendor advisory
  6. 2026-09-20 20:15 UTCEPSS rescore
  7. 2026-09-20 05:52 UTCVendor advisory
  8. 2026-09-20 01:47 UTCEG score recompute
  9. 2026-09-20 01:47 UTCVendor advisory
  10. 2026-09-18 22:34 UTCEG score recompute
  11. 2026-09-18 22:34 UTCVendor advisory
  12. 2026-09-18 19:28 UTCEPSS rescore
  13. 2026-09-18 11:17 UTCVendor advisory
  14. 2026-09-18 07:12 UTCVendor advisory
  15. 2026-09-18 03:06 UTCEG score recompute
  16. 2026-09-18 03:06 UTCVendor advisory
  17. 2026-09-17 19:31 UTCEPSS rescore
  18. 2026-09-17 09:17 UTCVendor advisory
  19. 2026-09-17 02:02 UTCEG score recompute
  20. 2026-09-17 02:02 UTCVendor advisory
  21. 2026-09-16 14:08 UTCEPSS rescore
  22. 2026-09-16 12:00 UTCVendor advisory
  23. 2026-09-16 06:46 UTCEG score recompute
  24. 2026-09-16 06:46 UTCVendor advisory
  25. 2026-09-16 05:15 UTCEPSS rescore
  26. 2026-09-14 16:14 UTCVendor advisory
  27. 2026-09-14 10:44 UTCVendor advisory
  28. 2026-09-14 06:33 UTCVendor advisory
  29. 2026-09-14 02:28 UTCVendor advisory
  30. 2026-09-13 22:22 UTCEG score recompute
  31. 2026-09-13 22:22 UTCVendor advisory
  32. 2026-09-13 16:47 UTCEPSS rescore
  33. 2026-09-13 15:28 UTCVendor advisory
  34. 2026-09-13 11:13 UTCVendor advisory
  35. 2026-09-13 06:32 UTCVendor advisory
  36. 2026-09-13 02:26 UTCVendor advisory
  37. 2026-09-12 22:19 UTCVendor advisory
  38. 2026-09-12 17:42 UTCEG score recompute
  39. 2026-09-12 17:42 UTCVendor advisory
  40. 2026-09-12 15:01 UTCEPSS rescore
  41. 2026-09-12 13:22 UTCVendor advisory
  42. 2026-09-12 09:16 UTCVendor advisory
  43. 2026-09-12 05:11 UTCVendor advisory
  44. 2026-09-12 01:00 UTCVendor advisory
  45. 2026-09-11 20:55 UTCVendor advisory
  46. 2026-09-11 16:45 UTCEG score recompute
  47. 2026-09-11 16:45 UTCVendor advisory
  48. 2026-09-11 14:53 UTCEPSS rescore
  49. 2026-09-11 09:37 UTCEPSS rescore
  50. 2026-09-11 07:17 UTCVendor advisory
  51. 2026-09-11 03:09 UTCVendor advisory
  52. 2026-09-10 20:56 UTCVendor advisory
  53. 2026-09-10 15:10 UTCEG score recompute
  54. 2026-09-10 15:10 UTCVendor advisory
  55. 2026-09-10 09:34 UTCEPSS rescore
  56. 2026-09-09 08:56 UTCEG score recompute
  57. 2026-09-09 08:56 UTCVendor advisory
  58. 2026-09-08 22:00 UTCEPSS rescore
  59. 2026-09-08 01:36 UTCVendor advisory
  60. 2026-09-07 21:30 UTCEG score recompute
  61. 2026-09-07 21:30 UTCVendor advisory
  62. 2026-09-07 16:01 UTCEPSS rescore
  63. 2026-09-06 16:49 UTCEG score recompute
  64. 2026-09-06 16:49 UTCVendor advisory
  65. 2026-09-06 13:47 UTCEPSS rescore
  66. 2026-09-06 12:42 UTCVendor advisory
  67. 2026-09-06 08:30 UTCVendor advisory
  68. 2026-09-06 03:39 UTCVendor advisory
  69. 2026-09-05 23:33 UTCVendor advisory
  70. 2026-09-05 19:28 UTCEG score recompute
  71. 2026-09-05 19:28 UTCVendor advisory
  72. 2026-09-05 06:58 UTCVendor advisory
  73. 2026-09-04 17:37 UTCEG score recompute
  74. 2026-09-04 17:37 UTCVendor advisory
  75. 2026-09-04 13:16 UTCEG score recompute

Related CVEs(same product + same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-45623?
CVE-2026-45623 is a critical vulnerability published on July 23, 2026. PostCSS takes a CSS file and provides an API to analyze and modify its rules by transforming the rules into an Abstract Syntax Tree. In versions 8.5.11 and prior, the PreviousMap parses the /# sourceMappingURL=PATH / comment from any CSS string passed to process() and dereferences PATH against the…
When was CVE-2026-45623 disclosed?
CVE-2026-45623 was first published on July 23, 2026, with the most recent update on August 7, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-45623 actively exploited?
CVE-2026-45623 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.6% probability of exploitation in the next 30 days (47th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-45623?
CVE-2026-45623 has a CVSS v3 base score of 9.1 (NVD).
How do I remediate CVE-2026-45623?
A fix for CVE-2026-45623 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-45623 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-45623

Explore →

Is Your Infrastructure Affected by CVE-2026-45623?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Book a Demo →Browse All CVEs