CVE-2021-34121

Name: CVE-2021-34121
Creator: NVD / NIST
Published: 2023-07-18T14:15:11.78+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.8/10EPSS 0.31%

Last modified Jun 17, 2026

CVE-2021-34121 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. 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.. EPSS estimates a 0.31% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1

7.8/10

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

EPSS Probability

0.31%

22.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-125

Affected Software

Vendor	Product	Versions
Htmldoc Project	Htmldoc	1.9.12

References

https://github.com/michaelrsweet/htmldoc/commit/c67bbd8756f015e33e4ba639a40c7f9d8bd9e8abPatch
https://github.com/michaelrsweet/htmldoc/issues/433Exploit, Issue Tracking
https://github.com/michaelrsweet/htmldoc/commit/c67bbd8756f015e33e4ba639a40c7f9d8bd9e8abPatch
https://github.com/michaelrsweet/htmldoc/issues/433Exploit, Issue Tracking

Timeline

Published: Jul 18, 2023
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-34121?

How severe is CVE-2021-34121?

CVE-2021-34121 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 0.31% probability of exploitation in the next 30 days.

How do I fix CVE-2021-34121?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-34121?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST