What is CVE-2021-40985?

CVE-2021-40985 is a medium-severity vulnerability in Htmldoc Project, classified under Out-of-bounds Read. CVSS score: 5.5/10. Published 2021-11-03.

How severe is CVE-2021-40985?

Medium severity. CVSS v3 base score is 5.5 out of 10.

Out-of-bounds Read in Htmldoc Project

CVE-2021-40985

A stack-based buffer under-read in htmldoc before 1.9.12, allows attackers to cause a denial of service via a crafted BMP image to image_load_bmp.

Vulnerability class: Buffer Overflow

Published 2021-11-03 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.009 (59.3th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 59th percentile — 59.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: 0.000

Affected products

Htmldoc Project
Debian Linux — versions 9.0

Weakness classification (CWE)

CWE-125 — Out-of-bounds Read

References

github.com/michaelrsweet/htmldoc/commit/f12b9666e582a8e7b70f11b28e5ffc49ad625d43 (Patch, Third Party Advisory)
github.com/michaelrsweet/htmldoc/issues/444 (Exploit, Patch, Third Party Advisory, Issue Tracking)
lists.debian.org/debian-lts-announce/2022/02/msg00022.html (mailing-list, Mailing List, Third Party Advisory)

Frequently asked questions

What is CVE-2021-40985?: CVE-2021-40985 is a medium-severity vulnerability in Htmldoc Project, classified under Out-of-bounds Read. CVSS score: 5.5/10. Published 2021-11-03.
How severe is CVE-2021-40985?: Medium severity. CVSS v3 base score is 5.5 out of 10.