Vulnerability · Published Sep 5, 2026 · Assigned by mitre
CVE-2026-86139
Medium 6.9
In plain English
A medium-severity integer overflow in libxml2 from xmlsoft. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 6% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)6.9Medium
Exploit odds (30 days)0.2%top 94.1% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
In libxml2 before 2.15.4, xmlURIEscapeStr in uri.c has an integer overflow.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:13 | libxml2 | no fix listed | DEBIAN-CVE-2026-86139 |
| Debian:14 | libxml2 | 2.15.4+dfsg-1 | DEBIAN-CVE-2026-86139 |
| Ubuntu:22.04:LTS | libxml2 | 2.9.13+dfsg-1ubuntu0.14 | USN-8910-1 |
| Ubuntu:24.04:LTS | libxml2 | 2.9.14+dfsg-1.3ubuntu3.10 | USN-8910-1 |
| Ubuntu:26.04:LTS | libxml2 | 2.15.2+dfsg-0.1ubuntu0.3 | UBUNTU-CVE-2026-86139 |
| Ubuntu:26.04:LTS | libxml2 | 2.15.2+dfsg-0.1ubuntu0.3 | USN-8910-1 |
Affected products (as reported)
Weakness: CWE-190 · Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L