CVE-2026-9358
postcss-selector-parser AST Serialization container.js toString recursion
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Passive
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
5.3
postcss-selector-parser AST Serialization container.js toString recursion
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.
- Record
CVE-2026-9358- CVSS 4.0
- 5.3 Medium
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 - CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L/E:P/RL:O/RC:C - CVSS 3.0
- 4.3 Medium
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L/E:P/RL:O/RC:C - CVSS 2.0
- 5.0
AV:N/AC:L/Au:N/C:N/I:N/A:P/E:POC/RL:OF/RC:C - Weakness
- CWE-674, CWE-404
- Updated
- 2026-11-02
EUVDEUVD-2026-31571
5.3
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.
- Record
EUVD-2026-31571- CVSS 4.0
- 5.3 Medium
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 - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-w9m9-85wc-3x92
2.1
postcss-selector-parser allows denial of service through uncontrolled AST recursion
A vulnerability was determined in postcss-selector-parser before 6.1.3 and 7.1.1. 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. 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)."
- Record
GHSA-w9m9-85wc-3x92- CVSS 4.0
- 2.1 Low
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 - CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L - Weakness
- CWE-404
- Updated
- 2026-11-02
NVD
2.1
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.
- Record
CVE-2026-9358- CVSS 4.0
- 2.1 Low
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 - CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L - CVSS 2.0
- 5.0 Medium
AV:N/AC:L/Au:N/C:N/I:N/A:P - Weakness
- CWE-404, CWE-674
- Updated
- 2026-11-02
OSV
2.1
postcss-selector-parser AST Serialization container.js toString recursion
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.
- Record
CVE-2026-9358- CVSS 4.0
- 2.1 Low
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 - Weakness
- CWE-404, CWE-674
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2026-9358
2.1
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.
- Record
DEBIAN-CVE-2026-9358- CVSS 4.0
- 2.1 Low
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 - Updated
- 2026-11-02
Show 6 moreShow less
OSVGHSA-w9m9-85wc-3x92
2.1
postcss-selector-parser allows denial of service through uncontrolled AST recursion
A vulnerability was determined in postcss-selector-parser before 6.1.3 and 7.1.1. 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. 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)."
- Record
GHSA-w9m9-85wc-3x92- CVSS 4.0
- 2.1 Low
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 - CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L - Weakness
- CWE-404
- Updated
- 2026-11-02
OSVRHSA-2026:22934
7.5
Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update
- Record
RHSA-2026:22934- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVUBUNTU-CVE-2026-9358
2.1
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.
- Record
UBUNTU-CVE-2026-9358- CVSS 4.0
- 2.1 Low
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 - CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L - Updated
- 2026-11-02
OSVCLSA-2026-1792450509 No score
TuxCare security update for postcss-selector-parser (2 CVEs)
TuxCare rebuilt postcss-selector-parser to address 2 CVEs. Fixed in 7.1.0-tuxcare.1.
- Record
CLSA-2026-1792450509- Updated
- 2026-11-02
OSVCLSA-2026-1792476079 No score
TuxCare security update for postcss-selector-parser (2 CVEs)
TuxCare rebuilt postcss-selector-parser to address 2 CVEs. Fixed in 6.1.2-tuxcare.1.
- Record
CLSA-2026-1792476079- Updated
- 2026-11-02
OSVCLSA-2026-1792489937 No score
TuxCare security update for postcss-selector-parser (2 CVEs)
TuxCare rebuilt postcss-selector-parser to address 2 CVEs. Fixed in 7.1.1-tuxcare.1.
- Record
CLSA-2026-1792489937- Updated
- 2026-11-02
Affected packages
| Package | Affected | Fixed |
|---|---|---|
postcss-selector-parsernpm |
6.1.0 up to 6.1.3 | 6.1.3 |
postcss-selector-parsernpm |
7.1.0 up to 7.1.3 | 7.1.3 |
postcss-selector-parserTuxCare:npm From an advisory covering 2 CVEs |
7.1.0-tuxcare.0 up to 7.1.0-tuxcare.1, plus listed versions 7.1.0 |
7.1.0-tuxcare.1 |
postcss-selector-parserTuxCare:npm From an advisory covering 2 CVEs |
6.1.2-tuxcare.0 up to 6.1.2-tuxcare.1, plus listed versions 6.1.2 |
6.1.2-tuxcare.1 |
postcss-selector-parserTuxCare:npm From an advisory covering 2 CVEs |
7.1.1-tuxcare.0 up to 7.1.1-tuxcare.1, plus listed versions 7.1.1 |
7.1.1-tuxcare.1 |
node-css-loaderDebian:12 |
All versions, plus listed versions 6.11.0+~cs15.5.7-16.11.0+~cs15.5.7-26.11.0+~cs15.5.7-36.7.2+~cs14.0.11-16.8.1+~cs14.0.17-16.8.1+~cs14.0.17-26.8.1+~cs14.1.4-1 |
None known |
node-css-loaderDebian:13 |
All versions, plus listed versions 6.11.0+~cs15.5.7-16.11.0+~cs15.5.7-26.11.0+~cs15.5.7-36.8.1+~cs14.0.17-16.8.1+~cs14.0.17-26.8.1+~cs14.1.4-1 |
None known |
node-css-loaderDebian:14 |
before 6.8.1+~cs14.1.4-1, plus listed versions 6.8.1+~cs14.0.17-16.8.1+~cs14.0.17-2 |
6.8.1+~cs14.1.4-1 |
cargoRed Hat:hummingbird:1 From an advisory covering 6 CVEs |
before 0:1.96.0-1.hum1 | 0:1.96.0-1.hum1 |
clippyRed Hat:hummingbird:1 From an advisory covering 6 CVEs |
before 0:1.96.0-1.hum1 | 0:1.96.0-1.hum1 |
Show 23 moreShow less
| Package | Affected | Fixed |
|---|---|---|
rustRed Hat:hummingbird:1 From an advisory covering 6 CVEs |
before 0:1.96.0-1.hum1 | 0:1.96.0-1.hum1 |
rust-analyzerRed Hat:hummingbird:1 From an advisory covering 6 CVEs |
before 0:1.96.0-1.hum1 | 0:1.96.0-1.hum1 |
rust-debugger-commonRed Hat:hummingbird:1 From an advisory covering 6 CVEs |
before 0:1.96.0-1.hum1 | 0:1.96.0-1.hum1 |
rust-docRed Hat:hummingbird:1 From an advisory covering 6 CVEs |
before 0:1.96.0-1.hum1 | 0:1.96.0-1.hum1 |
rust-gdbRed Hat:hummingbird:1 From an advisory covering 6 CVEs |
before 0:1.96.0-1.hum1 | 0:1.96.0-1.hum1 |
rust-lldbRed Hat:hummingbird:1 From an advisory covering 6 CVEs |
before 0:1.96.0-1.hum1 | 0:1.96.0-1.hum1 |
rust-srcRed Hat:hummingbird:1 From an advisory covering 6 CVEs |
before 0:1.96.0-1.hum1 | 0:1.96.0-1.hum1 |
rust-std-staticRed Hat:hummingbird:1 From an advisory covering 6 CVEs |
before 0:1.96.0-1.hum1 | 0:1.96.0-1.hum1 |
rust-std-static-aarch64-unknown-none-softfloatRed Hat:hummingbird:1 From an advisory covering 6 CVEs |
before 0:1.96.0-1.hum1 | 0:1.96.0-1.hum1 |
rust-std-static-aarch64-unknown-uefiRed Hat:hummingbird:1 From an advisory covering 6 CVEs |
before 0:1.96.0-1.hum1 | 0:1.96.0-1.hum1 |
rust-std-static-i686-pc-windows-gnuRed Hat:hummingbird:1 From an advisory covering 6 CVEs |
before 0:1.96.0-1.hum1 | 0:1.96.0-1.hum1 |
rust-std-static-wasm32-unknown-unknownRed Hat:hummingbird:1 From an advisory covering 6 CVEs |
before 0:1.96.0-1.hum1 | 0:1.96.0-1.hum1 |
rust-std-static-wasm32-wasip1Red Hat:hummingbird:1 From an advisory covering 6 CVEs |
before 0:1.96.0-1.hum1 | 0:1.96.0-1.hum1 |
rust-std-static-x86_64-pc-windows-gnuRed Hat:hummingbird:1 From an advisory covering 6 CVEs |
before 0:1.96.0-1.hum1 | 0:1.96.0-1.hum1 |
rust-std-static-x86_64-unknown-noneRed Hat:hummingbird:1 From an advisory covering 6 CVEs |
before 0:1.96.0-1.hum1 | 0:1.96.0-1.hum1 |
rust-std-static-x86_64-unknown-uefiRed Hat:hummingbird:1 From an advisory covering 6 CVEs |
before 0:1.96.0-1.hum1 | 0:1.96.0-1.hum1 |
rustfmtRed Hat:hummingbird:1 From an advisory covering 6 CVEs |
before 0:1.96.0-1.hum1 | 0:1.96.0-1.hum1 |
node-css-loaderUbuntu:20.04:LTS |
All versions, plus listed versions 1.0.1-11.0.1+repack-1 |
None known |
node-css-loaderUbuntu:22.04:LTS |
All versions, plus listed versions 5.0.1+~cs14.0.5-1 |
None known |
node-css-loaderUbuntu:24.04:LTS |
All versions, plus listed versions 6.7.2+~cs14.0.11-16.8.1+~cs14.0.17-1 |
None known |
node-css-loaderUbuntu:25.10 |
All versions, plus listed versions 6.8.1+~cs14.0.17-1 |
None known |
node-css-loaderUbuntu:26.10 |
All versions, plus listed versions 6.8.1+~cs14.0.17-26.8.1+~cs14.1.4-16.11.0+~cs15.5.7-16.11.0+~cs15.5.7-2 |
None known |
node-css-loaderUbuntu:26.04:LTS |
All versions, plus listed versions 6.8.1+~cs14.0.17-16.8.1+~cs14.0.17-2 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | ||
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-9358 is a medium vulnerability (CVSS 5.3) in postcss-selector-parser, published May 24, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.33%, the 25th percentile. Fixed in postcss-selector-parser 6.1.3.
References
vuldb.com/vuln/365321
vuldb.com/vuln/365321/cti
vuldb.com/cve/CVE-2026-9358
vuldb.com/submit/813080
gist.github.com/bx33661/581e3a38134601c04e19b4dfc9b459b9
github.com/postcss/postcss-selector-parser/commit/5bc698cef66f8abd12610dc623e5d67cbc0f869d
Show 43 moreShow less
github.com/postcss/postcss-selector-parser/releases/tag/7.1.3
nvd.nist.gov/vuln/detail/CVE-2026-9358
github.com/postcss/postcss-selector-parser/commit/e37c5b0b785b165e27508d2489fdec8e0f18b10a
github.com/postcss/postcss-selector-parser/releases/tag/6.1.3
github.com/advisories/GHSA-w9m9-85wc-3x92
github.com/CVEProject/cvelistV5/tree/main/cves/2026/9xxx/CVE-2026-9358.json
security-tracker.debian.org/tracker/CVE-2026-9358
github.com/postcss/postcss-selector-parser
access.redhat.com/errata/RHSA-2026:22934
images.redhat.com
access.redhat.com/security/cve/CVE-2026-45149
access.redhat.com/security/updates/classification
access.redhat.com/security/cve/CVE-2026-9358
access.redhat.com/security/cve/CVE-2026-9697
access.redhat.com/security/cve/CVE-2026-6734
access.redhat.com/security/cve/CVE-2026-9675
access.redhat.com/security/cve/CVE-2026-44432
access.redhat.com/security/cve/CVE-2026-51221
security.access.redhat.com/data/csaf/v2/advisories/2026/rhsa-2026_22934.json
bugzilla.redhat.com/show_bug.cgi?id=2490024
cve.org/CVERecord?id=CVE-2026-6734
nvd.nist.gov/vuln/detail/CVE-2026-6734
cna.openjsf.org/security-advisories.html
github.com/nodejs/undici/security/advisories/GHSA-hm92-r4w5-c3mj
bugzilla.redhat.com/show_bug.cgi?id=2481006
cve.org/CVERecord?id=CVE-2026-9358
bugzilla.redhat.com/show_bug.cgi?id=2489979
cve.org/CVERecord?id=CVE-2026-9675
nvd.nist.gov/vuln/detail/CVE-2026-9675
github.com/nodejs/undici/security/advisories/GHSA-38rv-x7px-6hhq
bugzilla.redhat.com/show_bug.cgi?id=2490018
cve.org/CVERecord?id=CVE-2026-9697
nvd.nist.gov/vuln/detail/CVE-2026-9697
github.com/nodejs/undici/security/advisories/GHSA-vmh5-mc38-953g
bugzilla.redhat.com/show_bug.cgi?id=2477154
cve.org/CVERecord?id=CVE-2026-44432
nvd.nist.gov/vuln/detail/CVE-2026-44432
github.com/urllib3/urllib3/security/advisories/GHSA-mf9v-mfxr-j63j
bugzilla.redhat.com/show_bug.cgi?id=2483481
cve.org/CVERecord?id=CVE-2026-45149
nvd.nist.gov/vuln/detail/CVE-2026-45149
github.com/juliangruber/brace-expansion/security/advisories/GHSA-jxxr-4gwj-5jf2
ubuntu.com/security/CVE-2026-9358