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Public proof of conceptFix availableAwaiting NVD analysis

CVE-2026-49825

A public proof of concept exists; no exploitation attested.

  • Published2026-08-20
  • Fixed in0.4.5
  • WeaknessCWE-184 · CWE-79

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

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.

Timeline

dates in UTC
  1. 2026-08-2015:17CVE publishedNVD

Versions per branch

OSV
lxml-html-clean
BranchAffectedFixed in
0.4< 0.4.50.4.5

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Products declared by the CNA2 products

As GitHub_M, the CNA that assigned this CVE, declared them in the CVE record; versions as written.

  • lxml
    Affected
    • = < 6.1.1no fix stated
  • fedora-python lxml_html_clean
    Affected
    • = < 0.4.5no fix stated

Source: the CNA record (CVE Program), © The MITRE Corporation,CVE Terms of UseCVE recordupdated 2026-08-20

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • foremanRed Hat:satellite:6.17::el9all versions · fixed in 0:3.14.0.22-1.el9satand 14 other packages
  • foremanRed Hat:satellite:6.16::el9all versions · fixed in 0:3.12.0.23-1.el9satand 14 other packages
  • foremanRed Hat:satellite:6.16::el8all versions · fixed in 0:3.12.0.23-1.el8satand 14 other packages
  • foremanRed Hat:satellite_utils:6.17::el9all versions · fixed in 0:3.14.0.22-1.el9satand 1 other package
  • foremanRed Hat:satellite_utils:6.16::el9all versions · fixed in 0:3.12.0.23-1.el9satand 1 other package
  • foremanRed Hat:satellite_utils:6.16::el8all versions · fixed in 0:3.12.0.23-1.el8satand 1 other package
  • foremanRed Hat:satellite_capsule:6.17::el9all versions · fixed in 0:3.14.0.22-1.el9satand 2 other packages
  • foremanRed Hat:satellite_capsule:6.16::el9all versions · fixed in 0:3.12.0.23-1.el9satand 2 other packages

247 more package ranges on OSV.dev

Vendor advisories

  • CVE-2026-49825 Red Hat Product Security256 products fixed · 167 known affected

    lxml: lxml-html-clean: lxml: URL bypass vulnerability in Cleaner via missing xlink:href

    lightspeed-core/lightspeed-stack-rhel9 as a component of Lightspeed Core · lightspeed-core/rag-tool-cpu-rhel9 as a component of Lightspeed Core · lightspeed-core/rag-tool-cuda-12.9-rhel9 as a component of Lightspeed Core · +164 more

  • RHSA-2026:90336 Red Hat Product Security7 products fixed

    Red Hat Security Advisory: python-lxml security update

  • RHSA-2026:90327 Red Hat Product Security10 products fixed

    Red Hat Security Advisory: python-lxml security update

  • RHSA-2026:90326 Red Hat Product Security17 products fixed

    Red Hat Security Advisory: python-lxml security update

  • RHSA-2026:87410 Red Hat Product Security6 products fixed

    Red Hat Security Advisory: RHOAI 2.25.12 - Red Hat OpenShift AI

  • RHSA-2026:86891 Red Hat Product Security6 products fixed

    Red Hat Security Advisory: RHOAI 3.5.2 - Red Hat OpenShift AI

24 more advisories

Full record on NVD

Fix

  1. Update lxml-html-clean to 0.4.5
  2. Vendor fix Red Hat Product Security RHSA-2026:90336 · 7 productsFor details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258
  3. Vendor fix Red Hat Product Security RHSA-2026:87410 · 6 productsFor Red Hat OpenShift AI 2.25.12 see the following documentation, which will be updated shortly for this release, for important instructions on how to upgrade your cluster and fully apply this errata update: https://docs.redhat.com/en/documentation/red_hat_openshift_ai/
  4. Vendor fix Red Hat Product Security RHSA-2026:86891 · 6 productsFor Red Hat OpenShift AI 3.5.2 see the following documentation, which will be updated shortly for this release, for important instructions on how to upgrade your cluster and fully apply this errata update: https://docs.redhat.com/en/documentation/red_hat_openshift_ai/
  5. Vendor fix Red Hat Product Security RHSA-2026:84734 · 13 productsFor Red Hat OpenShift AI 3.4.5 see the following documentation, which will be updated shortly for this release, for important instructions on how to upgrade your cluster and fully apply this errata update: https://docs.redhat.com/en/documentation/red_hat_openshift_ai/
  6. Vendor fix Red Hat Product Security RHSA-2026:81110 · 4 productsBefore applying this update, make sure all previously released errata relevant to your system have been applied.
  7. Vendor fix Red Hat Product Security RHSA-2026:79546 · 4 productsBefore applying this update, make sure all previously released errata relevant to your system have been applied. For details on how to apply this update, refer to: https://access.redhat.com/articles/11258

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof of concept
Metasploit modules
none listed
Metasploit Framework

Sources

  • NVDCVE recordread 2026-10-26
  • CISA-ADPSSVC decisionpoc2026-08-21
  • CNACVSS 3.18.2known since 2026-10-26
  • CNAweakness (CWE)CWE-184, CWE-79known since 2026-10-26
  • FIRST EPSSEPSS score0.3 %2026-11-09
  • OSVaffected packages—
  • GitHub AdvisoriesadvisoryHIGH2026-07-08

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N
Published
2026-08-20
Last Modified
2026-10-26
NVD status
Awaiting Analysis
GitHub Advisory
GHSA-4jhm-jv67-739f

Frequently asked questions

What is CVE-2026-49825?

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.

Is CVE-2026-49825 actively exploited?

A proof-of-concept exploit exists for CVE-2026-49825, but active exploitation has not been confirmed at this time.

What is the CVSS score for CVE-2026-49825?

CVE-2026-49825 has a CVSS v3 base score of 8.2 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N.

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