Vulnerability-Lookup

WID-SEC-W-2026-2930

Vulnerability from csaf_certbund - Published: 2026-08-19 22:00 - Updated: 2026-08-31 22:00

Summary

expat: Schwachstelle ermöglicht nicht spezifizierten Angriff

Severity

Mittel

Notes

Das BSI ist als Anbieter für die eigenen, zur Nutzung bereitgestellten Inhalte nach den allgemeinen Gesetzen verantwortlich. Nutzerinnen und Nutzer sind jedoch dafür verantwortlich, die Verwendung und/oder die Umsetzung der mit den Inhalten bereitgestellten Informationen sorgfältig im Einzelfall zu prüfen.

Produktbeschreibung: Expat ist ein XML Parser, der in der Programmiersprache-C geschrieben ist.

Angriff: Ein lokaler Angreifer kann eine Schwachstelle in expat ausnutzen, um einen nicht näher spezifizierten Angriff durchzuführen.

Betroffene Betriebssysteme: - Linux - UNIX

CVE-2026-76957

Affected products

Known affected 3 products

Product	Identifier	Version
Debian Linux Debian	`cpe:/o:debian:debian_linux:-`	—
Red Hat Enterprise Linux Red Hat	`cpe:/o:redhat:enterprise_linux:-`	—
Open Source expat <2.8.4 Open Source / expat		<2.8.4

References

5 references

URL	Category
https://wid.cert-bund.de/.well-known/csaf/white/2…	self
https://wid.cert-bund.de/portal/wid/securityadvis…	self
https://github.com/advisories/GHSA-vfgp-2986-rm7g	external
https://access.redhat.com/errata/RHSA-2026:60451	external
https://lists.debian.org/debian-lts-announce/2026…	external

JSON

To clipboard

{
  "document": {
    "aggregate_severity": {
      "text": "mittel"
    },
    "category": "csaf_base",
    "csaf_version": "2.0",
    "distribution": {
      "tlp": {
        "label": "WHITE",
        "url": "https://www.first.org/tlp/"
      }
    },
    "lang": "de-DE",
    "notes": [
      {
        "category": "legal_disclaimer",
        "text": "Das BSI ist als Anbieter f\u00fcr die eigenen, zur Nutzung bereitgestellten Inhalte nach den allgemeinen Gesetzen verantwortlich. Nutzerinnen und Nutzer sind jedoch daf\u00fcr verantwortlich, die Verwendung und/oder die Umsetzung der mit den Inhalten bereitgestellten Informationen sorgf\u00e4ltig im Einzelfall zu pr\u00fcfen."
      },
      {
        "category": "description",
        "text": "Expat ist ein XML Parser, der in der Programmiersprache-C geschrieben ist.",
        "title": "Produktbeschreibung"
      },
      {
        "category": "summary",
        "text": "Ein lokaler Angreifer kann eine Schwachstelle in expat ausnutzen, um einen nicht n\u00e4her spezifizierten Angriff durchzuf\u00fchren.",
        "title": "Angriff"
      },
      {
        "category": "general",
        "text": "- Linux\n- UNIX",
        "title": "Betroffene Betriebssysteme"
      }
    ],
    "publisher": {
      "category": "other",
      "contact_details": "csaf-provider@cert-bund.de",
      "name": "Bundesamt f\u00fcr Sicherheit in der Informationstechnik",
      "namespace": "https://www.bsi.bund.de"
    },
    "references": [
      {
        "category": "self",
        "summary": "WID-SEC-W-2026-2930 - CSAF Version",
        "url": "https://wid.cert-bund.de/.well-known/csaf/white/2026/wid-sec-w-2026-2930.json"
      },
      {
        "category": "self",
        "summary": "WID-SEC-2026-2930 - Portal Version",
        "url": "https://wid.cert-bund.de/portal/wid/securityadvisory?name=WID-SEC-2026-2930"
      },
      {
        "category": "external",
        "summary": "GitHub Security Advisory GHSA-vfgp-2986-rm7g vom 2026-08-19",
        "url": "https://github.com/advisories/GHSA-vfgp-2986-rm7g"
      },
      {
        "category": "external",
        "summary": "Red Hat Security Advisory RHSA-2026:60451 vom 2026-08-27",
        "url": "https://access.redhat.com/errata/RHSA-2026:60451"
      },
      {
        "category": "external",
        "summary": "Debian Security Advisory DLA-4765 vom 2026-08-31",
        "url": "https://lists.debian.org/debian-lts-announce/2026/08/msg00057.html"
      }
    ],
    "source_lang": "en-US",
    "title": "expat: Schwachstelle erm\u00f6glicht nicht spezifizierten Angriff",
    "tracking": {
      "current_release_date": "2026-08-31T22:00:00.000+00:00",
      "generator": {
        "date": "2026-09-01T08:07:36.080+00:00",
        "engine": {
          "name": "BSI-WID",
          "version": "1.6.0"
        }
      },
      "id": "WID-SEC-W-2026-2930",
      "initial_release_date": "2026-08-19T22:00:00.000+00:00",
      "revision_history": [
        {
          "date": "2026-08-19T22:00:00.000+00:00",
          "number": "1",
          "summary": "Initiale Fassung"
        },
        {
          "date": "2026-08-27T22:00:00.000+00:00",
          "number": "2",
          "summary": "Neue Updates von Red Hat aufgenommen"
        },
        {
          "date": "2026-08-31T22:00:00.000+00:00",
          "number": "3",
          "summary": "Neue Updates von Debian aufgenommen"
        }
      ],
      "status": "final",
      "version": "3"
    }
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "category": "product_name",
            "name": "Debian Linux",
            "product": {
              "name": "Debian Linux",
              "product_id": "2951",
              "product_identification_helper": {
                "cpe": "cpe:/o:debian:debian_linux:-"
              }
            }
          }
        ],
        "category": "vendor",
        "name": "Debian"
      },
      {
        "branches": [
          {
            "branches": [
              {
                "category": "product_version_range",
                "name": "\u003c2.8.4",
                "product": {
                  "name": "Open Source expat \u003c2.8.4",
                  "product_id": "T058365"
                }
              },
              {
                "category": "product_version",
                "name": "2.8.4",
                "product": {
                  "name": "Open Source expat 2.8.4",
                  "product_id": "T058365-fixed",
                  "product_identification_helper": {
                    "cpe": "cpe:/a:expat:expat:2.8.4"
                  }
                }
              }
            ],
            "category": "product_name",
            "name": "expat"
          }
        ],
        "category": "vendor",
        "name": "Open Source"
      },
      {
        "branches": [
          {
            "category": "product_name",
            "name": "Red Hat Enterprise Linux",
            "product": {
              "name": "Red Hat Enterprise Linux",
              "product_id": "67646",
              "product_identification_helper": {
                "cpe": "cpe:/o:redhat:enterprise_linux:-"
              }
            }
          }
        ],
        "category": "vendor",
        "name": "Red Hat"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2026-76957",
      "product_status": {
        "known_affected": [
          "2951",
          "67646",
          "T058365"
        ]
      },
      "release_date": "2026-08-19T22:00:00.000+00:00",
      "title": "CVE-2026-76957"
    }
  ]
}

CVE-2026-76957 (GCVE-0-2026-76957)

Vulnerability from cvelistv5 – Published: 2026-08-20 04:28 – Updated: 2026-08-20 15:26

Summary

libexpat before 2.8.4 lacks handler call depth tracking with custom encoding callbacks. Thus, a use-after-free can occur. NOTE: this is similar to CVE-2026-50219, CVE-2026-56131 and CVE-2026-56412.

Severity

4.9 (Medium)


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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-20 15:05 UTC

CWE

CWE-416 - Use After Free

Assigner

mitre CNA under the mitre root

CNA scorecard E 28/100 over 2316 records in the last 180 days details

References

2 references

URL	Tags
https://github.com/libexpat/libexpat/pull/1322
https://github.com/libexpat/libexpat/pull/1329

Impacted products

1 product

Vendor	Product	Version
libexpat project	libexpat	Affected: 0 , < 2.8.4 (semver) cpe:2.3:a:libexpat_project:libexpat::::::::

Show details on NVD website

JSON

To clipboard

{
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            "other": {
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                "id": "CVE-2026-76957",
                "options": [
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                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-20T15:05:41.792254Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
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    ],
    "cna": {
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              "status": "affected",
              "version": "0",
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            }
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      ],
      "cpeApplicability": [
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                  "criteria": "cpe:2.3:a:libexpat_project:libexpat:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "2.8.4",
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                }
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              "operator": "OR"
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        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
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            "attackVector": "LOCAL",
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    "dateReserved": "2026-08-20T04:28:04.012Z",
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    "state": "PUBLISHED"
  },
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}

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.

Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

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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.

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