Vulnerability-Lookup

OESA-2026-3217 (CVE-2026-49825)

Vulnerability from osv_openeuler – Published: 2026-08-01 11:12 – Updated: 2026-08-06 11:12 – Source website

Summary

python-lxml security update

Details

Security Fix(es):

lxml_html_clean.Cleaner does not strip javascript: URLs from namespaced URL attributes (xlink:href). The vulnerability exists because Cleaner filters URL schemes by walking links via rewrite_links(), which delegates to iterlinks(), which only yields attributes named in lxml.html.defs.link_attrs. That allow-list contains no prefixed names such as xlink:href. As a result, when Cleaner is configured with safe_attrs_only=False, an xlink:href attribute carrying a javascript: URL survives sanitization untouched, and any browser that follows the SVG or MathML anchor specification will execute the JavaScript when the rendered link is clicked, leading to Cross-Site Scripting (XSS) attacks.(CVE-2026-49825)

Severity

8.2 (High)


                    
                      CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N

References

URL

Type

	https://www.openeuler.org/zh/security/security-bu…	ADVISORY
	https://nvd.nist.gov/vuln/detail/CVE-2026-49825	ADVISORY

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "aarch64": [
          "python-lxml-debuginfo-5.1.0-5.oe2403sp1.aarch64.rpm",
          "python-lxml-debugsource-5.1.0-5.oe2403sp1.aarch64.rpm",
          "python-lxml-help-5.1.0-5.oe2403sp1.aarch64.rpm",
          "python3-lxml-5.1.0-5.oe2403sp1.aarch64.rpm"
        ],
        "src": [
          "python-lxml-5.1.0-5.oe2403sp1.src.rpm"
        ],
        "x86_64": [
          "python-lxml-debuginfo-5.1.0-5.oe2403sp1.x86_64.rpm",
          "python-lxml-debugsource-5.1.0-5.oe2403sp1.x86_64.rpm",
          "python-lxml-help-5.1.0-5.oe2403sp1.x86_64.rpm",
          "python3-lxml-5.1.0-5.oe2403sp1.x86_64.rpm"
        ]
      },
      "package": {
        "ecosystem": "openEuler:24.03-LTS-SP1",
        "name": "python-lxml",
        "purl": "pkg:rpm/openEuler/python-lxml\u0026distro=openEuler-24.03-LTS-SP1"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "5.1.0-5.oe2403sp1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "aarch64": [
          "python-lxml-debuginfo-5.1.0-5.oe2403sp3.aarch64.rpm",
          "python-lxml-debugsource-5.1.0-5.oe2403sp3.aarch64.rpm",
          "python-lxml-help-5.1.0-5.oe2403sp3.aarch64.rpm",
          "python3-lxml-5.1.0-5.oe2403sp3.aarch64.rpm"
        ],
        "src": [
          "python-lxml-5.1.0-5.oe2403sp3.src.rpm"
        ],
        "x86_64": [
          "python-lxml-debuginfo-5.1.0-5.oe2403sp3.x86_64.rpm",
          "python-lxml-debugsource-5.1.0-5.oe2403sp3.x86_64.rpm",
          "python-lxml-help-5.1.0-5.oe2403sp3.x86_64.rpm",
          "python3-lxml-5.1.0-5.oe2403sp3.x86_64.rpm"
        ]
      },
      "package": {
        "ecosystem": "openEuler:24.03-LTS-SP3",
        "name": "python-lxml",
        "purl": "pkg:rpm/openEuler/python-lxml\u0026distro=openEuler-24.03-LTS-SP3"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "5.1.0-5.oe2403sp3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "aarch64": [
          "python-lxml-debuginfo-5.1.0-5.oe2403sp4.aarch64.rpm",
          "python-lxml-debugsource-5.1.0-5.oe2403sp4.aarch64.rpm",
          "python-lxml-help-5.1.0-5.oe2403sp4.aarch64.rpm",
          "python3-lxml-5.1.0-5.oe2403sp4.aarch64.rpm"
        ],
        "src": [
          "python-lxml-5.1.0-5.oe2403sp4.src.rpm"
        ],
        "x86_64": [
          "python-lxml-debuginfo-5.1.0-5.oe2403sp4.x86_64.rpm",
          "python-lxml-debugsource-5.1.0-5.oe2403sp4.x86_64.rpm",
          "python-lxml-help-5.1.0-5.oe2403sp4.x86_64.rpm",
          "python3-lxml-5.1.0-5.oe2403sp4.x86_64.rpm"
        ]
      },
      "package": {
        "ecosystem": "openEuler:24.03-LTS-SP4",
        "name": "python-lxml",
        "purl": "pkg:rpm/openEuler/python-lxml\u0026distro=openEuler-24.03-LTS-SP4"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "5.1.0-5.oe2403sp4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "aarch64": [
          "python-lxml-debuginfo-4.5.2-11.oe2003sp4.aarch64.rpm",
          "python-lxml-debugsource-4.5.2-11.oe2003sp4.aarch64.rpm",
          "python2-lxml-4.5.2-11.oe2003sp4.aarch64.rpm",
          "python3-lxml-4.5.2-11.oe2003sp4.aarch64.rpm"
        ],
        "noarch": [
          "python-lxml-help-4.5.2-11.oe2003sp4.noarch.rpm"
        ],
        "src": [
          "python-lxml-4.5.2-11.oe2003sp4.src.rpm"
        ],
        "x86_64": [
          "python-lxml-debuginfo-4.5.2-11.oe2003sp4.x86_64.rpm",
          "python-lxml-debugsource-4.5.2-11.oe2003sp4.x86_64.rpm",
          "python2-lxml-4.5.2-11.oe2003sp4.x86_64.rpm",
          "python3-lxml-4.5.2-11.oe2003sp4.x86_64.rpm"
        ]
      },
      "package": {
        "ecosystem": "openEuler:20.03-LTS-SP4",
        "name": "python-lxml",
        "purl": "pkg:rpm/openEuler/python-lxml\u0026distro=openEuler-20.03-LTS-SP4"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.5.2-11.oe2003sp4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "aarch64": [
          "python-lxml-debuginfo-4.7.1-10.oe2203sp4.aarch64.rpm",
          "python-lxml-debugsource-4.7.1-10.oe2203sp4.aarch64.rpm",
          "python3-lxml-4.7.1-10.oe2203sp4.aarch64.rpm"
        ],
        "noarch": [
          "python-lxml-help-4.7.1-10.oe2203sp4.noarch.rpm"
        ],
        "src": [
          "python-lxml-4.7.1-10.oe2203sp4.src.rpm"
        ],
        "x86_64": [
          "python-lxml-debuginfo-4.7.1-10.oe2203sp4.x86_64.rpm",
          "python-lxml-debugsource-4.7.1-10.oe2203sp4.x86_64.rpm",
          "python3-lxml-4.7.1-10.oe2203sp4.x86_64.rpm"
        ]
      },
      "package": {
        "ecosystem": "openEuler:22.03-LTS-SP4",
        "name": "python-lxml",
        "purl": "pkg:rpm/openEuler/python-lxml\u0026distro=openEuler-22.03-LTS-SP4"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.7.1-10.oe2203sp4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "severity": "High"
  },
  "details": "\\\r\n\r\nSecurity Fix(es):\n\nlxml_html_clean.Cleaner does not strip javascript: URLs from namespaced URL attributes (xlink:href). The vulnerability exists because Cleaner filters URL schemes by walking links via rewrite_links(), which delegates to iterlinks(), which only yields attributes named in lxml.html.defs.link_attrs. That allow-list contains no prefixed names such as xlink:href. As a result, when Cleaner is configured with safe_attrs_only=False, an xlink:href attribute carrying a javascript: URL survives sanitization untouched, and any browser that follows the SVG or MathML anchor specification will execute the JavaScript when the rendered link is clicked, leading to Cross-Site Scripting (XSS) attacks.(CVE-2026-49825)",
  "id": "OESA-2026-3217",
  "modified": "2026-08-06T11:12:05Z",
  "published": "2026-08-01T11:12:05Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2026-3217"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-49825"
    }
  ],
  "schema_version": "1.7.2",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "python-lxml security update",
  "upstream": [
    "CVE-2026-49825"
  ]
}

CVE-2026-49825 (GCVE-0-2026-49825)

Vulnerability from cvelistv5 – Published: 2026-08-20 14:42 – Updated: 2026-08-21 16:41

Title

lxml: javascript: URL bypass in Cleaner via xlink:href

Summary

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.

Severity

8.2 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N

SSVC

Exploitation: poc Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-21 16:41 UTC

CWE

CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CWE-184 - Incomplete List of Disallowed Inputs

Assigner

GitHub_M mitre root

References

5 references

URL	Tags
https://github.com/fedora-python/lxml_html_clean/…	x_refsource_CONFIRM
https://github.com/fedora-python/lxml_html_clean/…	x_refsource_MISC
https://github.com/lxml/lxml/commit/5927a6d5e8518…	x_refsource_MISC
https://github.com/fedora-python/lxml_html_clean/…	x_refsource_MISC
https://github.com/lxml/lxml/releases/tag/lxml-6.1.1	x_refsource_MISC

Impacted products

2 products

Vendor	Product	Version
lxml	lxml	Affected: < 6.1.1
fedora-python	lxml_html_clean	Affected: < 0.4.5

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-49825",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-21T16:41:32.043801Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
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        "providerMetadata": {
          "dateUpdated": "2026-08-21T16:41:54.849Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
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            "tags": [
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            "url": "https://github.com/fedora-python/lxml_html_clean/security/advisories/GHSA-4jhm-jv67-739f"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "lxml",
          "vendor": "lxml",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 6.1.1"
            }
          ]
        },
        {
          "product": "lxml_html_clean",
          "vendor": "fedora-python",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 0.4.5"
            }
          ]
        }
      ],
      "descriptions": [
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          "lang": "en",
          "value": "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."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 8.2,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
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            "userInteraction": "REQUIRED",
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            }
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        {
          "descriptions": [
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          "url": "https://github.com/fedora-python/lxml_html_clean/security/advisories/GHSA-4jhm-jv67-739f"
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          "url": "https://github.com/fedora-python/lxml_html_clean/commit/322357ac61c6cf80fcbaba53b4e92e31f3ded9f2"
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          "url": "https://github.com/lxml/lxml/commit/5927a6d5e851845140975d99b65461e255caaab0"
        },
        {
          "name": "https://github.com/fedora-python/lxml_html_clean/releases/tag/0.4.5",
          "tags": [
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      "source": {
        "advisory": "GHSA-4jhm-jv67-739f",
        "discovery": "UNKNOWN"
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      "title": "lxml: javascript: URL bypass in Cleaner via xlink:href"
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  "cveMetadata": {
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    "datePublished": "2026-08-20T14:42:30.748Z",
    "dateReserved": "2026-06-01T18:50:36.055Z",
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    "state": "PUBLISHED"
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  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

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