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CVE-2018-20843

In libexpat in Expat before 2.2.7, XML input including XML names that contain a large number of colons could make the XML parser consume a high amount of RAM and CPU resources whil

Published Jun 24, 2019 · updated Oct 15, 2026 · libexpat project libexpat

In libexpat in Expat before 2.2.7, XML input including XML names that contain a large number of colons could make the XML parser consume a high amount of RAM and CPU resources while processing (enough to be usable for denial-of-service attacks).

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Jun 24, 2019 · NIST NVD

    Detected

    In libexpat in Expat before 2.2.7, XML input including XML names that contain a large number of colons could make the XML parser consume a high amount of RAM and CPU resources while processing (enough to be usable for denial-of-service attacks).

  2. Oct 14, 2026 · NIST NVD

    Updated

    In libexpat in Expat before 2.2.7, XML input including XML names that contain a large number of colons could make the XML parser consume a high amount of RAM and CPU resources while processing (enough to be usable for denial-of-service attacks).

  3. Oct 14, 2026 · OSV.dev

    Fix available

    expat fixed in 2.2.6-2; expat fixed in 2.2.6-2; expat fixed in 2.2.6-2

  4. Oct 14, 2026 · OSV.dev

    Fix available

    expat fixed in 2.2.6-2

  5. Oct 14, 2026 · OSV.dev

    Updated

    In libexpat in Expat before 2.2.7, XML input including XML names that contain a large number of colons could make the XML parser consume a high amount of RAM and CPU resources while processing (enough to be usable for denial-of-service attacks).

  6. Oct 15, 2026 · OSV.dev

    Updated

    In libexpat in Expat before 2.2.7, XML input including XML names that contain a large number of colons could make the XML parser consume a high amount of RAM and CPU resources while processing (enough to be usable for denial-of-service attacks).

  7. Oct 15, 2026 · OSV.dev

    Updated

    In libexpat in Expat before 2.2.7, XML input including XML names that contain a large number of colons could make the XML parser consume a high amount of RAM and CPU resources while processing (enough to be usable for denial-of-service attacks).

Affected

  • Debian:12 expat0 → 2.2.6-2
  • Debian:12 libxmltok1.2-4, 1.2-4.1, 1.2-4.1~exp1
  • Debian:13 expat0 → 2.2.6-2
  • Debian:14 expat0 → 2.2.6-2
  • cpe canonical/ubuntu linux12.04
  • cpe canonical/ubuntu linux14.04
  • cpe canonical/ubuntu linux16.04
  • cpe canonical/ubuntu linux18.04
  • cpe canonical/ubuntu linux18.10
  • cpe canonical/ubuntu linux19.04
  • cpe debian/debian linux8.0
  • cpe fedoraproject/fedora29
  • cpe libexpat project/libexpatversion unspecified
  • cpe opensuse/leap15.0
  • cpe oracle/hospitality res 3700version unspecified
  • cpe tenable/nessusversion unspecified

Sources

  • CVE.orgVulnerability recordCVE-2018-20843

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2018-20843

    30-day exploitation probability 7.1%

    first.org
  • NIST NVDVulnerability recordCVE-2018-20843

    In libexpat in Expat before 2.2.7, XML input including XML names that contain a large number of colons could make the XML parser consume a high amount of RAM and CPU resources while processing (enough to be usable for denial-of-service attacks).

    nvd.nist.gov
  • OSV.devPackage advisoryDEBIAN-CVE-2018-20843
    osv.dev

References