DEBIAN-CVE-2026-66046

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Source
https://security-tracker.debian.org/tracker/CVE-2026-66046
Import Source
https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-66046.json
JSON Data
https://api.test.osv.dev/v1/vulns/DEBIAN-CVE-2026-66046
Upstream
Published
2026-08-18T15:16:57Z
Modified
2026-09-04T17:00:09Z
Severity
  • 8.7 (High) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/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 Calculator
Summary
[none]
Details

Expat through 2.8.3 contains a denial of service vulnerability caused by quadratic algorithmic complexity in the storeAtts() function in xmlparse.c, where processing N specified attributes with non-normalized values triggers an O(N^2) linear scan of elementType->defaultAtts to determine CDATA status. A remote unauthenticated attacker can supply a single well-formed XML document of a few megabytes to an application parsing untrusted XML to cause excessive CPU consumption, resulting in denial of service without requiring authentication, external entity resolution, or non-default parser options.

References

Affected packages

Debian:12 / expat

Package

Name
expat
Purl
pkg:deb/debian/expat?arch=source&distro=bookworm

Affected ranges

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

Affected versions

2.*
2.5.0-1
2.5.0-1+deb12u1
2.5.0-1+deb12u2
2.5.0-1+deb12u3
2.5.0-2
2.6.0-1
2.6.1-1
2.6.1-2
2.6.2-1
2.6.2-2
2.6.3-1
2.6.3-2
2.6.4-1
2.7.0-1
2.7.1-1
2.7.1-2
2.7.2-1
2.7.3-1
2.7.3-2
2.7.4-1
2.7.5-1
2.8.0-1
2.8.0-2
2.8.1-1
2.8.2-1~deb13u1
2.8.2-1
2.8.3-1~deb13u1
2.8.3-1
2.8.4-1

Ecosystem specific 

{
    "urgency": "not yet assigned"
}

Database specific

source 
"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-66046.json"

Debian:13 / expat

Package

Name
expat
Purl
pkg:deb/debian/expat?arch=source&distro=trixie

Affected ranges

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

Affected versions

2.*
2.7.1-2
2.7.2-1
2.7.3-1
2.7.3-2
2.7.4-1
2.7.5-1
2.8.0-1
2.8.0-2
2.8.1-1
2.8.2-1~deb13u1
2.8.2-1
2.8.3-1~deb13u1
2.8.3-1
2.8.4-1

Ecosystem specific 

{
    "urgency": "not yet assigned"
}

Database specific

source 
"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-66046.json"

Debian:14 / expat

Package

Name
expat
Purl
pkg:deb/debian/expat?arch=source&distro=forky

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
2.8.4-1

Affected versions

2.*
2.7.1-2
2.7.2-1
2.7.3-1
2.7.3-2
2.7.4-1
2.7.5-1
2.8.0-1
2.8.0-2
2.8.1-1
2.8.2-1~deb13u1
2.8.2-1
2.8.3-1~deb13u1
2.8.3-1

Ecosystem specific 

{
    "urgency": "not yet assigned"
}

Database specific

source 
"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-66046.json"