libxml2 · NULL Pointer Dereference
Affects libxml2Source GCVE Database
Not known to be exploited · CVSS 5.5 Medium : update libxml2 when convenient.
Data as of 5 Nov 2026, 00:01 UTC
Thin evidence
One scorer or none| CNA (redhat) | CVSS 3.1 | 5.5 |
|---|
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 4% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 17 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 5 Nov 2026.
What to do
Patches and advisories
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlibxml2pkg:deb/ubuntu/libxml2?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlibxml2pkg:deb/ubuntu/libxml2?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSlibxml2pkg:deb/ubuntu/libxml2?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Ubuntu Pro 20.04 LTSlibxml2pkg:deb/ubuntu/libxml2?arch=source&distro=esm-infra/focalOther threats | Affected
| Fixed in– |
Ubuntu Pro 18.04 LTSlibxml2pkg:deb/ubuntu/libxml2?arch=source&distro=esm-infra/bionicOther threats | Affected
| Fixed in– |
Ubuntu Pro 16.04 LTSlibxml2pkg:deb/ubuntu/libxml2?arch=source&distro=esm-infra-legacy/xenialOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Red Hat has released an official security update that fixes this vulnerability. Users should apply the updated libxml2 packages (version 2.15.3-0.1.3.hum1) provided by Red Hat. Additionally, users should avoid processing untrusted XML catalog files and restrict applications from loading external XML catalogs unless they are trusted. No further action is required once the update is applied.
Description
A flaw was found in libxml2. A local user or an attacker providing a specially crafted XML catalog can trigger a NULL pointer dereference during XML catalog parsing. This occurs when a `nextCatalog` element lacks its mandatory `catalog` attribute, leading to the application crashing and causing a Denial of Service (DoS).
References
- nvd.nist.gov/vuln/detail/CVE-2026-76781 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:57604 (opens in a new tab)
- access.redhat.com/security/cve/CVE-2026-76781 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2519776 (opens in a new tab)
- gitlab.gnome.org/GNOME/libxml2/-/commit/c6324894 (opens in a new tab)
- gitlab.gnome.org/GNOME/libxml2/-/merge_requests/442 (opens in a new tab)
- ubuntu.com/security/CVE-2026-76781 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-76781 (opens in a new tab)