Vulnerability · Published Sep 5, 2026 · Assigned by mitre
CVE-2026-86140
High 8.0
In plain English
A high-severity stack buffer 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 5% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)8.0High
Exploit odds (30 days)0.2%top 95.1% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
In libxml2 before 2.15.4, xmlSnprintfElements in valid.c has a strcat stack-based buffer overflow.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:10 | libxml2 | 2.12.5-10.el10_2.4 | ALSA-2026:71586 |
| AlmaLinux:8 | libxml2 | 2.9.7-21.el8_10.9 | ALSA-2026:71641 |
| AlmaLinux:9 | libxml2 | 2.9.13-14.el9_8.5 | ALSA-2026:71585 |
| AlmaLinux:10 | libxml2-devel | 2.12.5-10.el10_2.4 | ALSA-2026:71586 |
| AlmaLinux:8 | libxml2-devel | 2.9.7-21.el8_10.9 | ALSA-2026:71641 |
| AlmaLinux:9 | libxml2-devel | 2.9.13-14.el9_8.5 | ALSA-2026:71585 |
| AlmaLinux:10 | libxml2-static | 2.12.5-10.el10_2.4 | ALSA-2026:71586 |
| AlmaLinux:10 | python3-libxml2 | 2.12.5-10.el10_2.4 | ALSA-2026:71586 |
| AlmaLinux:8 | python3-libxml2 | 2.9.7-21.el8_10.9 | ALSA-2026:71641 |
| AlmaLinux:9 | python3-libxml2 | 2.9.13-14.el9_8.5 | ALSA-2026:71585 |
| Debian:12 | libxml2 | no fix listed | DEBIAN-CVE-2026-86140 |
| Debian:13 | libxml2 | no fix listed | DEBIAN-CVE-2026-86140 |
| Debian:14 | libxml2 | 2.15.4+dfsg-1 | DEBIAN-CVE-2026-86140 |
| Rocky Linux:10 | libxml2 | 0:2.12.5-10.el10_2.4 | RLSA-2026:71586 |
| Rocky Linux:8 | libxml2 | 0:2.9.7-21.el8_10.9 | RLSA-2026:71641 |
| Rocky Linux:9 | libxml2 | 0:2.9.13-14.el9_8.5 | RLSA-2026:71585 |
| Ubuntu:22.04:LTS | libxml2 | 2.9.13+dfsg-1ubuntu0.13 | UBUNTU-CVE-2026-86140 |
| Ubuntu:22.04:LTS | libxml2 | 2.9.13+dfsg-1ubuntu0.13 | USN-8787-1 |
| Ubuntu:24.04:LTS | libxml2 | 2.9.14+dfsg-1.3ubuntu3.9 | USN-8787-1 |
| Ubuntu:24.04:LTS | libxml2 | 2.9.14+dfsg-1.3ubuntu3.9 | UBUNTU-CVE-2026-86140 |
| Ubuntu:26.04:LTS | libxml2 | 2.15.2+dfsg-0.1ubuntu0.2 | USN-8787-1 |
| Ubuntu:26.04:LTS | libxml2 | 2.15.2+dfsg-0.1ubuntu0.2 | UBUNTU-CVE-2026-86140 |
Affected products (as reported)
Weakness: CWE-121 · Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L