A vulnerability was determined in postcss-selector-parser up to 6.1.2/7.1.2. Affected is the function toString of the file src/selectors/container.js of the component AST Serialization. Executing a manipulation can lead to uncontrolled recursion. It is possible to launch the attack remotely. The exploit has been publicly disclosed and may be utilized. Upgrading to version 6.1.3 and 7.1.3 is able to address this issue. This patch is called 5bc698cef66f8abd12610dc623e5d67cbc0f869d. It is suggested to upgrade the affected component. The vendor explains, that according to his definition "DoS on server-side on user-generated CSS is low risk for us (since most users compile own CSS with PostCSS)." The commits were backported to 6.x branch, which was the most downloaded version.
CVE-2026-9358
“—” beside the score: it is equal to the CVSS score beside it.
Score 4.3 from GitHub Security Advisory (severity: LOW) published 2026-05-26. A secondary CVSS source baseline 4.3; sources differ by 0.0.
Also known asEUVD-2026-31571 (ENISA EUVD) · GHSA-w9m9-85wc-3x92 (GitHub Security Advisories)Source: ENISA EUVD
- CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
A fix is available — apply it.
- CVSS v3
- 4.3
- EG Score
- 4.3MEDIUMmedium confidence
- EG Risk
- 35EG Risk 35/100
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)Severity43% × 45%Impact severity (EG Severity): CVSS 4.3 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.Automatability0% × 15%CISA's SSVC Automatable value: no (Vulnrichment).SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).Exploitation public PoC (CISA Vulnrichment) · Automatable no (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. - EPSS PROB
- 0.3%
- EPSS %ILE
- 25th
- 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 (4.3): severity, escalated by confirmed exploitation. This CVE's 4.3 is its impact severity (EG Severity), not escalated.
- EG Severity
- 4.3 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- 0.3% within 30 daysSource: FIRST EPSS. 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; Track* at high (mission-essential systems).CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade 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; Track* at high (mission-essential systems).
A fix is available. Apply it within your standard update timelines.
Exploitation public PoC (CISA Vulnrichment) · Automatable no (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)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (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
May 24, 2026
Last Modified
July 23, 2026
Advisory Details (3)
Auto-updated Jun 15, 20267.1.3
Patch available: postcss/postcss-selector-parser 7.1.3
https://github.com/postcss/postcss-selector-parser/releases/tag/7.1.3commit 5bc698cef66f (postcss/postcss-selector-parser)
Patch available: postcss/postcss-selector-parser 7.1.3 (contains commit 5bc698cef66f)
https://github.com/postcss/postcss-selector-parser/commit/5bc698cef66f8abd12610dc623e5d67cbc0f869dUncontrolled Recursion in AST Serialization (toString) Leads to Stack Overflow DoS · GitHub
https://gist.github.com/bx33661/581e3a38134601c04e19b4dfc9b459b9Vendor Advisories for CVE-2026-9358(4)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
- RHSA-2026:56928Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat OpenShift Data Foundation 4.22.2 security, enhancement & bug fix update
- RHSA-2026:56431Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat OpenShift Data Foundation 4.18.27 security, enhancement & bug fix update
- RHSA-2026:22934Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update
- GHSA-w9m9-85wc-3x92GitHub Security AdvisoriesLow
postcss-selector-parser allows denial of service through uncontrolled AST recursion
Patch Availability(3)
| Vendor / Ecosystem | Fix (by version range) / Patch | Released | Source |
|---|---|---|---|
| redhat | odf4/rook-ceph-rhel9-operator:1787061554 | 2026-08-19 | redhat |
| redhat | odf4/rook-ceph-rhel9-operator:1786706880 | 2026-08-18 | redhat |
| redhat | rust-main-1.96.0-1.hum1 | 2026-06-03 | redhat |
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)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| node-css-loader | 5.0.1+~cs14.0.5-1 ... 6.8.1+~cs14.1.4-1 (7 versions) |
| — |
Debian:12(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| node-css-loader | 6.11.0+~cs15.5.7-1 ... 6.8.1+~cs14.1.4-1 (7 versions) |
| — |
Debian:13(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| node-css-loader | 6.11.0+~cs15.5.7-1 ... 6.8.1+~cs14.1.4-1 (6 versions) |
| — |
Debian:14(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| node-css-loader | 6.8.1+~cs14.0.17-1, 6.8.1+~cs14.0.17-2 |
| — |
npm(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| postcss-selector-parser | — |
| — |
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 8× in last 7d / 38× 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 98 of 249 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. 2 repeat rows among the latest 100 are merged into the row they repeat. The 151 oldest rows on record are not shown and were not checked, so the counts can still include repeats.
- 2026-11-02 16:46 UTCEPSS rescoreEPSS 0.3% · 25th percentile
- 2026-11-01 16:36 UTCEPSS rescoreEPSS 0.3% · 25th percentile
- 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.3% · 25th percentile
- 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.3% · 25th percentile
- 2026-10-29 21:55 UTCOSV refresh
- 2026-10-29 16:34 UTCEPSS rescoreEPSS 0.3% · 25th percentile
- 2026-10-28 16:33 UTCEPSS rescoreEPSS 0.3% · 25th percentile
- 2026-10-27 16:33 UTCEPSS rescoreEPSS 0.3% · 25th percentile
- 2026-10-26 16:33 UTCEPSS rescoreEPSS 0.3% · 25th percentile
- 2026-10-25 16:34 UTCEPSS rescoreEPSS 0.3% · 25th percentile
- 2026-10-25 13:49 UTCEG score recompute
- 2026-10-24 16:34 UTCEPSS rescoreEPSS 0.6% · 47th percentile
- 2026-10-23 16:33 UTCEPSS rescoreEPSS 0.6% · 47th percentile
- 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.6% · 46th percentile
- 2026-10-22 12:28 UTCEG score recompute
- 2026-10-22 12:28 UTCVendor advisory
- 2026-10-21 16:34 UTCEPSS rescoreEPSS 0.6% · 46th percentile
- 2026-10-20 16:34 UTCEPSS rescoreEPSS 0.6% · 46th percentile
- 2026-10-19 16:34 UTCEPSS rescoreEPSS 0.6% · 46th percentile
- 2026-10-18 02:58 UTCEG score recompute
- 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.6% · 46th percentile
- 2026-10-16 16:45 UTCEPSS rescoreEPSS 0.6% · 46th percentile
- 2026-10-15 16:33 UTCEPSS rescoreEPSS 0.6% · 46th percentile
- 2026-10-14 16:34 UTCEPSS rescoreEPSS 0.6% · 46th percentile
- 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.6% · 46th percentile
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- 2026-10-12 16:35 UTCEPSS rescoreEPSS 0.6% · 46th percentile
- 2026-10-12 14:42 UTCEG score recompute
- 2026-10-11 19:12 UTCEG score recompute
- 2026-10-11 16:28 UTCEG score recompute
- 2026-10-11 13:50 UTCEPSS rescoreEPSS 0.6% · 46th percentile
- 2026-10-11 13:41 UTCEG score recompute
- 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.6% · 46th percentile
- 2026-10-09 20:08 UTCEPSS rescoreEPSS 0.6% · 46th percentile
- 2026-10-08 17:14 UTCEPSS rescoreEPSS 0.6% · 45th percentile
- 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.6% · 45th percentile
- 2026-10-06 15:19 UTCEPSS rescoreEPSS 0.6% · 45th percentile
- 2026-10-05 17:44 UTCEPSS rescoreEPSS 0.6% · 45th percentile
- 2026-10-04 23:23 UTCEPSS rescoreEPSS 0.6% · 45th percentile
- 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.6% · 45th percentile
- 2026-10-02 17:57 UTCEPSS rescoreEPSS 0.6% · 45th percentile
- 2026-10-01 19:51 UTCEPSS rescoreEPSS 0.6% · 45th percentile
- 2026-09-30 15:04 UTCEPSS rescoreEPSS 0.6% · 45th percentile
- 2026-09-30 02:39 UTCOSV refresh
- 2026-09-28 13:52 UTCEPSS rescoreEPSS 0.6% · 45th percentile
- 2026-09-27 13:49 UTCEPSS rescoreEPSS 0.6% · 45th percentile
- 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.6% · 45th percentile
- 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.6% · 45th percentile
- 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.3% · 25th percentile
- 2026-09-22 16:01 UTCEPSS rescoreEPSS 0.3% · 25th percentile
- 2026-09-21 21:09 UTCEPSS rescoreEPSS 0.3% · 25th percentile
- 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.3% · 25th percentile
- 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.3% · 25th percentile
- 2026-09-17 19:32 UTCEPSS rescoreEPSS 0.3% · 25th percentile
- 2026-09-16 14:09 UTCEPSS rescoreEPSS 0.3% · 25th percentile
- 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.3% · 25th percentile
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- 2026-09-13 16:48 UTCEPSS rescoreEPSS 0.3% · 25th percentile
- 2026-09-12 15:02 UTCEPSS rescoreEPSS 0.3% · 25th percentile
- 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.3% · 25th percentile
- 2026-09-11 09:38 UTCEPSS rescoreEPSS 0.3% · 25th percentile
- 2026-09-11 03:53 UTCOSV refresh
- 2026-09-10 09:35 UTCEPSS rescoreEPSS 0.3% · 25th percentile
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- 2026-09-06 13:48 UTCEPSS rescoreEPSS 0.3% · 25th percentile
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- 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.3% · 25th percentile
- 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.3% · 25th percentile
- 2026-09-01 04:40 UTCEPSS rescoreEPSS 0.3% · 25th percentile
- 2026-08-30 19:18 UTCEPSS rescoreEPSS 0.3% · 25th percentile
- 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.3% · 24th percentile
- 2026-08-28 21:42 UTCEPSS rescoreEPSS 0.3% · 24th percentile
- 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.3% · 24th percentile
- 2026-08-26 14:47 UTCEPSS rescoreEPSS 0.3% · 24th percentile
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- 2026-08-24 14:18 UTCEPSS rescoreEPSS 0.3% · 24th percentile
- 2026-08-23 16:37 UTCEG score recompute
- 2026-08-23 16:37 UTCVendor advisory
- 2026-08-23 16:37 UTCGHSA enrichmentGHSA-w9m9-85wc-3x92 · GitHub severity LOW · GitHub CVSS 4.3
- 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.3% · 25th percentile
- 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.3% · 25th percentile
- 2026-08-21 21:38 UTCEG score recompute
- 2026-08-21 21:38 UTCVendor advisory
- 2026-08-21 21:38 UTCGHSA enrichmentGHSA-w9m9-85wc-3x92 · GitHub severity LOW · GitHub CVSS 4.3
- 2026-08-20 22:56 UTCEPSS rescoreEPSS 0.3% · 25th percentile
- 2026-08-20 18:34 UTCEG score recompute
- 2026-08-20 18:34 UTCVendor advisory
- 2026-08-20 18:34 UTCGHSA enrichmentGHSA-w9m9-85wc-3x92 · GitHub severity LOW · GitHub CVSS 4.3
- 2026-08-19 17:04 UTCEPSS rescoreEPSS 0.3% · 25th percentile
- 2026-08-18 13:49 UTCEPSS rescoreEPSS 0.3% · 25th percentile
- 2026-08-17 13:47 UTCEPSS rescoreEPSS 0.3% · 25th percentile
- 2026-08-17 09:42 UTCEG score recompute
- 2026-08-17 09:42 UTCVendor advisory
- 2026-08-17 09:42 UTCGHSA enrichmentGHSA-w9m9-85wc-3x92 · GitHub severity LOW · GitHub CVSS 4.3
- 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.3% · 25th percentile
- 2026-08-16 03:17 UTCEG score recompute
- 2026-08-16 03:17 UTCVendor advisory
- 2026-08-16 03:17 UTCGHSA enrichmentGHSA-w9m9-85wc-3x92 · GitHub severity LOW · GitHub CVSS 4.3
Related CVEs(same product + same vendor + same CWE)
Same vendor
10 shownredhat:RHSA-2026:22934 · redhat:RHSA-2026:56431
Frequently asked(5)
What is CVE-2026-9358?
When was the CVE record for CVE-2026-9358 published?
Is CVE-2026-9358 actively exploited?
What is the CVSS score of CVE-2026-9358?
How do I remediate CVE-2026-9358?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-9358
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