CVE-2026-45623

CRITICALNVD 9.19.1
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to NVD's CVSS score.

This critical-severity CVE scores 9.1 under NVD CVSS v3. EPSS exploit probability: 0.6% (49th percentile of EPSS-scored CVEs). GitHub Security Advisory CVSS 7.5 is lower than this score; a lower GitHub score revises it only when its advisory is newer than the CVE record's last change, and this advisory (published 2026-07-23) is not newer than that change (2026-08-07), so it does not.

Triggered by: Headline CVSS from NVD CVSS v3
Sources: EPSS, GitHub Security Advisory, NVD CVSS v3
Trending — 4 sources updated this weekElevated

Also known asEUVD-2026-49376 (ENISA EUVD) · GHSA-6g55-p6wh-862q (GitHub Security Advisories)Source: ENISA EUVD

9.1EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
CISA-KEV: Not listedEPSS PROB: 0.6%CVSS: 9.1Exploit: No code on recordExposed 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
72
EG Risk 72/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity91% × 45%
Impact severity (EG Severity): CVSS 9.1 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation40% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).
Exploitation public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
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
49th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (9.1): severity, escalated by confirmed exploitation. This CVE's 9.1 is its impact severity (EG Severity), not escalated.

EG Severity
9.1 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.NVD CVSS v3 · CVSS v3.0 or v3.1
EG Likelihood
0.6% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-01). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at low or medium mission impact; Attend at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; 60 days if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; 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 public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; 60 days if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

July 23, 2026

Last Modified

August 7, 2026

Advisory Details (1)

Auto-updated Sep 16, 2026
Patch available. Sources: github.
GitHub advisoryMentions a patch (unverified)

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

Patch Availability(31)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatrhoai/odh-mod-arch-eval-hub-rhel9:17918612142026-10-19redhat
redhatrhtas/rekor-search-ui-rhel9:17915343392026-10-15redhat
redhatsatellite/iop-advisor-frontend-rhel9:17906933532026-10-01redhat
redhatcluster-observability-operator/prometheus-rhel9:17908579222026-10-01redhat
redhatopenshift4/ose-console-rhel9:17899395652026-10-01redhat
redhatforeman-0:3.18.0.14-1.el9sat2026-10-01redhat
redhatopenshift4/ose-console:17893692992026-09-24redhat
redhatopenshift4/ose-console-rhel9:17894537272026-09-24redhat
redhatopenshift4/ose-console:17893320712026-09-24redhat
redhatsatellite/iop-vulnerability-frontend-rhel9:17896609832026-09-17redhat
redhatopenshift4/ose-console-rhel9:17888059262026-09-17redhat
redhatdevspaces/dashboard-rhel9:17891628842026-09-17redhat
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
redhatdevspaces/openvsx-rhel9:17877591452026-09-01redhat
redhatopenshift4/ose-console-rhel9:17877463822026-09-01redhat
redhatdiscovery/discovery-ui-rhel9:17882061962026-08-31redhat
redhatrhoai/odh-mod-arch-model-registry-rhel9:17872506172026-08-27redhat
redhatrhacm2/console-rhel9:17873392482026-08-26redhat
redhatrhacm2/console-rhel9:17873351052026-08-26redhat
redhatrhacm2/console-rhel9:17873392492026-08-26redhat
redhatrhacm2/console-rhel9:17876870622026-08-26redhat
redhatmulticluster-engine/console-mce-rhel9:17870793592026-08-25redhat
redhatopenshift-service-mesh/kiali-rhel9:17870921982026-08-25redhat
redhatmulticluster-engine/console-mce-rhel9:17866688562026-08-25redhat
redhatopenshift-service-mesh/kiali-rhel9:17870922552026-08-25redhat
npmpostcss @ 8.5.12 (fixes <= 8.5.11)—ghsa

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

(20)

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 24× in last 7d / 83× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 100 of 341 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 241 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-02 02:54 UTCEG score recompute
  2. 2026-11-02 02:54 UTCVendor advisory
  3. 2026-11-02 02:54 UTCGHSA enrichmentGHSA-6g55-p6wh-862q · GitHub severity HIGH · GitHub CVSS 7.5
  4. 2026-11-01 16:34 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  5. 2026-11-01 07:48 UTCGHSA enrichmentGHSA-6g55-p6wh-862q · GitHub severity HIGH · GitHub CVSS 7.5
  6. 2026-11-01 07:48 UTCEG score recompute
  7. 2026-11-01 03:08 UTCEG score recompute
  8. 2026-11-01 03:08 UTCVendor advisory
  9. 2026-10-31 16:32 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  10. 2026-10-31 03:22 UTCEG score recompute
  11. 2026-10-31 03:22 UTCVendor advisory
  12. 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  13. 2026-10-30 03:37 UTCEG score recompute
  14. 2026-10-30 03:37 UTCVendor advisory
  15. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  16. 2026-10-29 03:52 UTCEG score recompute
  17. 2026-10-29 03:52 UTCVendor advisory
  18. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  19. 2026-10-28 04:05 UTCEG score recompute
  20. 2026-10-28 04:05 UTCVendor advisory
  21. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  22. 2026-10-27 04:04 UTCEG score recompute
  23. 2026-10-27 04:04 UTCVendor advisory
  24. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  25. 2026-10-25 23:59 UTCEG score recompute
Show 75 more
  1. 2026-10-25 23:59 UTCVendor advisory
  2. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  3. 2026-10-25 14:26 UTCEG score recompute
  4. 2026-10-25 00:13 UTCEG score recompute
  5. 2026-10-25 00:13 UTCVendor advisory
  6. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  7. 2026-10-24 00:28 UTCEG score recompute
  8. 2026-10-24 00:28 UTCVendor advisory
  9. 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  10. 2026-10-23 00:40 UTCEG score recompute
  11. 2026-10-23 00:40 UTCVendor advisory
  12. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  13. 2026-10-22 00:49 UTCEG score recompute
  14. 2026-10-22 00:49 UTCVendor advisory
  15. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  16. 2026-10-21 01:04 UTCEG score recompute
  17. 2026-10-21 01:04 UTCVendor advisory
  18. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  19. 2026-10-20 01:17 UTCEG score recompute
  20. 2026-10-20 01:17 UTCVendor advisory
  21. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  22. 2026-10-19 00:11 UTCEG score recompute
  23. 2026-10-19 00:11 UTCVendor advisory
  24. 2026-10-18 03:38 UTCEG score recompute
  25. 2026-10-18 00:23 UTCEG score recompute
  26. 2026-10-18 00:23 UTCVendor advisory
  27. 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  28. 2026-10-17 00:37 UTCEG score recompute
  29. 2026-10-17 00:37 UTCVendor advisory
  30. 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  31. 2026-10-16 00:27 UTCEG score recompute
  32. 2026-10-16 00:27 UTCVendor advisory
  33. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  34. 2026-10-14 18:59 UTCEG score recompute
  35. 2026-10-14 18:59 UTCVendor advisory
  36. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  37. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  38. 2026-10-13 15:23 UTCEG score recompute
  39. 2026-10-13 15:23 UTCVendor advisory
  40. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  41. 2026-10-12 15:34 UTCEG score recompute
  42. 2026-10-12 15:34 UTCVendor advisory
  43. 2026-10-12 07:45 UTCVendor advisory
  44. 2026-10-11 19:46 UTCEG score recompute
  45. 2026-10-11 17:00 UTCEG score recompute
  46. 2026-10-11 14:26 UTCEG score recompute
  47. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  48. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  49. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  50. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  51. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  52. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  53. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  54. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  55. 2026-10-04 12:43 UTCVendor advisory
  56. 2026-10-04 08:21 UTCEG score recompute
  57. 2026-10-04 08:21 UTCVendor advisory
  58. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  59. 2026-10-03 03:24 UTCEG score recompute
  60. 2026-10-03 03:24 UTCVendor advisory
  61. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  62. 2026-10-01 14:28 UTCVendor advisory
  63. 2026-10-01 10:22 UTCVendor advisory
  64. 2026-10-01 06:17 UTCEG score recompute
  65. 2026-10-01 06:17 UTCVendor advisory
  66. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  67. 2026-09-28 13:17 UTCVendor advisory
  68. 2026-09-28 09:11 UTCVendor advisory
  69. 2026-09-28 05:06 UTCEG score recompute
  70. 2026-09-28 05:06 UTCVendor advisory
  71. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  72. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  73. 2026-09-24 11:01 UTCVendor advisory
  74. 2026-09-24 06:35 UTCVendor advisory
  75. 2026-09-24 02:29 UTCVendor advisory

Frequently asked(5)

What is CVE-2026-45623?
CVE-2026-45623 is a critical-severity vulnerability; its CVE record was 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…
When was the CVE record for CVE-2026-45623 published?
The CVE record for CVE-2026-45623 was published on July 23, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of August 7, 2026; the record at its source may have been updated since.
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 (49th 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

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