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CVE-2026-49825VulnerabilityPublished Updated

lxml.html.defs.link_attrs were missing xlink:href · Prior to 6.1.1, link attributes

Affects lxmlSource GCVE Database

0
Authoritative record:CVE-2026-49825· High 8.2

Not known to be exploited · CVSS 8.2 High · fixed in 3.3.3-1ubuntu0.2+esm6 : patch lxml soon.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 3.1 base score
8.2High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.2% chance of exploitation in 30 days – higher than 22% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 3.3.3-1ubuntu0.2+esm6, 3.5.0-1ubuntu0.4+esm3, 4.2.1-1ubuntu0.6+esm1 +4
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 20 Aug 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq 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 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
Ubuntu 26.04 LTSlxmlpkg:deb/ubuntu/lxml?arch=source&distro=resoluteOther threatsAffected
  • <6.0.2-1ubuntu0.1
Fixed in
  • 6.0.2-1ubuntu0.1
Ubuntu 24.04 LTSlxmlpkg:deb/ubuntu/lxml?arch=source&distro=nobleOther threatsAffected
  • <5.2.1-1ubuntu0.2
Fixed in
  • 5.2.1-1ubuntu0.2
Ubuntu 22.04 LTSlxmlpkg:deb/ubuntu/lxml?arch=source&distro=jammyOther threatsAffected
  • <4.8.0-1ubuntu0.1
Fixed in
  • 4.8.0-1ubuntu0.1
Ubuntu Pro 20.04 LTSlxmlpkg:deb/ubuntu/lxml?arch=source&distro=esm-infra/focalOther threatsAffected
  • <4.5.0-1ubuntu0.5+esm1
Fixed in
  • 4.5.0-1ubuntu0.5+esm1
Ubuntu Pro 18.04 LTSlxmlpkg:deb/ubuntu/lxml?arch=source&distro=esm-infra/bionicOther threatsAffected
  • <4.2.1-1ubuntu0.6+esm1
Fixed in
  • 4.2.1-1ubuntu0.6+esm1
Ubuntu Pro 16.04 LTSlxmlpkg:deb/ubuntu/lxml?arch=source&distro=esm-infra-legacy/xenialOther threatsAffected
  • <3.5.0-1ubuntu0.4+esm3
Fixed in
  • 3.5.0-1ubuntu0.4+esm3

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

Description

lxml is a library for processing XML and HTML in the Python language. Prior to 6.1.1, link attributes in ``lxml.html.defs.link_attrs`` were missing ``xlink:href``, which can be used for URL bypass attacks in embedded SVG/MathML/etc. content. This vulnerability was fixed in lxml 6.1.1 and lxml_html_clean 0.4.5.

References

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