CVE-2026-66046
CVE-2026-66046 · Expat Denial of Service via storeAtts() Quadratic Complexity
This page contains facts from public vulnerability sources. Check the original advisory before updating.
This page shows selected source facts. See the linked advisories for the complete description and affected versions.
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.
CVSS 8.7 · High · EPSS 0.7% · Fix available
- Published
- Updated
Stack: system
Affected products and versions
libexpat
- Versions
- ≥ 0, ≤ 2.8.3: Affected (semver)
No fix published
expat Debian:12
- Versions
- 2.5.0-1
- 2.5.0-1+deb12u1
- 2.5.0-1+deb12u2
- 2.5.0-1+deb12u3
- Affected ranges
- ECOSYSTEM: < 2.5.0-1+deb12u4
Update to 2.5.0-1+deb12u4
expat Debian:13
- Versions
- 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
- 2.8.2-1~deb13u1
- 2.8.3-1
- 2.8.3-1~deb13u1
- 2.8.4-1
- 2.8.4-2
- 2.8.5-1
- 2.8.5-2
- Affected ranges
- ECOSYSTEM: < 2.9.0-1~deb13u1
Update to 2.9.0-1~deb13u1
expat Debian:14
- Versions
- 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
- 2.8.2-1~deb13u1
- 2.8.3-1
- 2.8.3-1~deb13u1
- Affected ranges
- ECOSYSTEM: < 2.8.4-1
Update to 2.8.4-1
coin3 Ubuntu:Pro:14.04:LTS
- Versions
- 3.1.4~abc9f50-3
- 3.1.4~abc9f50-4
- 3.1.4~abc9f50-4ubuntu2
- 3.1.4~abc9f50-4ubuntu2+esm1
- 3.1.4~abc9f50-4ubuntu2+esm2
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
expat Ubuntu:Pro:14.04:LTS
- Versions
- 2.1.0-4
- 2.1.0-4ubuntu1
- 2.1.0-4ubuntu1.1
- 2.1.0-4ubuntu1.2
- 2.1.0-4ubuntu1.3
- 2.1.0-4ubuntu1.4
- 2.1.0-4ubuntu1.4+esm1
- 2.1.0-4ubuntu1.4+esm2
- 2.1.0-4ubuntu1.4+esm4
- 2.1.0-4ubuntu1.4+esm6
- 2.1.0-4ubuntu1.4+esm7
- 2.1.0-4ubuntu1.4+esm8
- 2.1.0-4ubuntu1.4+esm9
- 2.1.0-4ubuntu1.4+esm10
- 2.1.0-4ubuntu1.4+esm11
- 2.1.0-4ubuntu1.4+esm12
- Affected ranges
- ECOSYSTEM: < 2.1.0-4ubuntu1.4+esm13
Update to 2.1.0-4ubuntu1.4+esm13
vnc4 Ubuntu:Pro:14.04:LTS
- Versions
- 4.1.1+xorg4.3.0-37ubuntu5
- 4.1.1+xorg4.3.0-37ubuntu5.0.1
- 4.1.1+xorg4.3.0-37ubuntu5.0.2
- 4.1.1+xorg4.3.0-37ubuntu5.0.2+esm1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
vtk Ubuntu:Pro:14.04:LTS
- Versions
- 5.8.0-14ubuntu1
- 5.8.0-14ubuntu3
- 5.8.0-14.1ubuntu2
- 5.8.0-14.1ubuntu3
- 5.8.0-14.1ubuntu3+esm1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
xmlrpc-c Ubuntu:Pro:14.04:LTS
- Versions
- 1.16.33-3.2ubuntu3
- 1.33.06-0ubuntu1
- 1.33.06-0ubuntu1+esm1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
expat Ubuntu:Pro:16.04:LTS
- Versions
- 2.1.0-7
- 2.1.0-7ubuntu0.16.04.1
- 2.1.0-7ubuntu0.16.04.2
- 2.1.0-7ubuntu0.16.04.3
- 2.1.0-7ubuntu0.16.04.4
- 2.1.0-7ubuntu0.16.04.5
- 2.1.0-7ubuntu0.16.04.5+esm2
- 2.1.0-7ubuntu0.16.04.5+esm5
- 2.1.0-7ubuntu0.16.04.5+esm6
- 2.1.0-7ubuntu0.16.04.5+esm7
- 2.1.0-7ubuntu0.16.04.5+esm8
- 2.1.0-7ubuntu0.16.04.5+esm9
- 2.1.0-7ubuntu0.16.04.5+esm10
- 2.1.0-7ubuntu0.16.04.5+esm11
- 2.1.0-7ubuntu0.16.04.5+esm12
- 2.1.0-7ubuntu0.16.04.5+esm13
- Affected ranges
- ECOSYSTEM: < 2.1.0-7ubuntu0.16.04.5+esm14
Update to 2.1.0-7ubuntu0.16.04.5+esm14
ayttm Ubuntu:Pro:16.04:LTS
- Versions
- 0.6.3-3build1
- 0.6.3-3ubuntu0.1~esm1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
cableswig Ubuntu:Pro:16.04:LTS
- Versions
- 0.1.0+git20150808-1
- 0.1.0+git20150808-2
- 0.1.0+git20150808-2ubuntu0.1~esm1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
cadaver Ubuntu:16.04:LTS
- Versions
- 0.23.3-2ubuntu2
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
coin3 Ubuntu:Pro:16.04:LTS
- Versions
- 3.1.4~abc9f50+dfsg1-1
- 3.1.4~abc9f50+dfsg1-1ubuntu0.1~esm1
- 3.1.4~abc9f50+dfsg1-1ubuntu0.1~esm2
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
insighttoolkit4 Ubuntu:16.04:LTS
- Versions
- 4.8.1-1ubuntu3
- 4.8.1-1ubuntu4
- 4.8.2-3.1ubuntu1
- 4.9.0-3ubuntu2
- 4.9.0-4ubuntu1
- 4.9.0-4ubuntu1.1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
libxmltok Ubuntu:Pro:16.04:LTS
- Versions
- 1.2-3build3
- 1.2-3ubuntu0.1~esm1
- 1.2-3ubuntu0.16.04.1~esm1
- 1.2-3ubuntu0.16.04.1~esm2
- 1.2-3ubuntu0.16.04.1~esm3
- 1.2-3ubuntu0.16.04.1~esm4
- 1.2-3ubuntu0.16.04.1~esm5
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
matanza Ubuntu:16.04:LTS
- Versions
- 0.13+ds1-5
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
smart Ubuntu:16.04:LTS
- Versions
- 1.4-2
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
swish-e Ubuntu:Pro:16.04:LTS
- Versions
- 2.4.7-4
- 2.4.7-4build1
- 2.4.7-4ubuntu0.1~esm1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
tdom Ubuntu:16.04:LTS
- Versions
- 0.8.3-1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
vnc4 Ubuntu:Pro:16.04:LTS
- Versions
- 4.1.1+xorg4.3.0-37.3ubuntu2
- 4.1.1+xorg4.3.0-37.3ubuntu2.1+esm1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
vtk Ubuntu:Pro:16.04:LTS
- Versions
- 5.10.1+dfsg-2
- 5.10.1+dfsg-2build3
- 5.10.1+dfsg-2.1build1
- 5.10.1+dfsg-2.1ubuntu0.1~esm1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
wbxml2 Ubuntu:16.04:LTS
- Versions
- 0.10.7-1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
xmlrpc-c Ubuntu:Pro:16.04:LTS
- Versions
- 1.33.14-0.2ubuntu3
- 1.33.14-1ubuntu1
- 1.33.14-1ubuntu1+esm1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published