Out-of-bounds Read Affecting htmldoc package, versions <1.8.27-8ubuntu1.1+esm2


Severity

Recommended
low

Based on Ubuntu security rating.

Threat Intelligence

EPSS
0.02% (7th percentile)

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  • Snyk IDSNYK-UBUNTU1604-HTMLDOC-5787417
  • published22 Mar 2026
  • disclosed18 Jul 2023

Introduced: 18 Jul 2023

CVE-2021-34121  (opens in a new tab)
CWE-125  (opens in a new tab)

How to fix?

Upgrade Ubuntu:16.04 htmldoc to version 1.8.27-8ubuntu1.1+esm2 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream htmldoc package and not the htmldoc package as distributed by Ubuntu. See How to fix? for Ubuntu:16.04 relevant fixed versions and status.

An Out of Bounds flaw was discovered in htmodoc 1.9.12 in function parse_tree() in toc.cxx, this possibly leads to memory layout information leaking in the data. This might be used in a chain of vulnerability in order to reach code execution.

CVSS Base Scores

version 3.1