UBUNTU-CVE-2026-45623

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Source
https://ubuntu.com/security/CVE-2026-45623
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-45623.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-45623
Upstream
Published
2026-07-27T18:16:00Z
Modified
2026-07-29T10:18:12.175393209Z
Severity
  • 7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

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.

References

Affected packages

Ubuntu:20.04:LTS / node-postcss

Package

Name
node-postcss
Purl
pkg:deb/ubuntu/node-postcss?arch=source&distro=focal

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

6.*
6.0.23-1
6.0.23-3

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "6.0.23-3",
            "binary_name": "node-postcss"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-45623.json"

Ubuntu:22.04:LTS / node-postcss

Package

Name
node-postcss
Purl
pkg:deb/ubuntu/node-postcss?arch=source&distro=jammy

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

8.*
8.2.1+~cs5.3.23-8
8.4.5+~cs7.1.51-2
8.4.6+~cs7.3.21-1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "8.4.6+~cs7.3.21-1",
            "binary_name": "node-postcss"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-45623.json"

Ubuntu:24.04:LTS / node-postcss

Package

Name
node-postcss
Purl
pkg:deb/ubuntu/node-postcss?arch=source&distro=noble

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

8.*
8.4.20+~cs8.0.23-1
8.4.31+~cs8.0.26-1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "8.4.31+~cs8.0.26-1",
            "binary_name": "node-postcss"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-45623.json"

Ubuntu:26.04:LTS / node-postcss

Package

Name
node-postcss
Purl
pkg:deb/ubuntu/node-postcss?arch=source&distro=resolute

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

8.*
8.5.6+~cs9.3.28-1
8.5.8+~cs9.3.30-1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "8.5.8+~cs9.3.30-1",
            "binary_name": "node-postcss"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-45623.json"