CVE-2026-9358

Exploitation

Public exploit code exists. CISA's assessment records a public proof of concept. That is not a report of exploitation in the wild.

SSVC decision

• ExploitationpocPublic proof-of-concept exploit code exists. Not a report of exploitation in the wild.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.33% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 25.2% of scored records. A rank, not a probability.

NVD base score

2.1 (CVSS v4.0), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

NVD analysis status

Deferred. NVD last modified this record on 2026-07-23.

Red Hat severity

Moderate. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2026-05-24 05:30Z3 MO AGO

Last updated

2026-06-15 07:21Z2 MO AGO

Reserved

2026-05-23

Assigning CNA

VulDB

Record state

PUBLISHED

Severity

Medium (CVSS 5.3)

CNA CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P

Weaknesses

• CWE-404Improper Resource Shutdown or ReleaseClass
• CWE-674Uncontrolled RecursionClass

Data version

5.2

Document digest

208b74e1cf6c2a110467f61dfb315f1e3c0867e14d8bb94b79875db5d37a1829

• vuldb.comVDB-365321 | postcss-selector-parser AST Serialization container.js toString recursionhttps://vuldb.com/vuln/365321vdb-entrytechnical-description
• vuldb.comVDB-365321 | CTI Indicators (IOB, IOC, TTP, IOA)https://vuldb.com/vuln/365321/ctisignaturepermissions-required
• vuldb.comCVE-2026-9358 | CVE Analysis and Reporthttps://vuldb.com/cve/CVE-2026-9358third-party-advisory
• vuldb.comSubmit #813080 | postcss-selector-parser postcss <= 7.1.1 CWE-674: Uncontrolled Recursionhttps://vuldb.com/submit/813080third-party-advisory
• gist.github.comhttps://gist.github.com/bx33661/581e3a38134601c04e19b4dfc9b459b9exploit
• github.comhttps://github.com/postcss/postcss-selector-parser/commit/5bc698cef66f8abd12610dc623e5d67cbc0f869dpatch
• github.comhttps://github.com/postcss/postcss-selector-parser/releases/tag/7.1.3patch