CVE-2021-40812: The GD Graphics Library (aka LibGD) through 2.3.2 has an out-of-bounds read because of the lack of certain gdG

Q: How do I fix CVE-2021-40812?

libgd: upgrade to newer than 2.3.2. Exact commands for each OS are on this page.

Q: Is CVE-2021-40812 being exploited?

CVE-2021-40812 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2021-40812 affect?

CVE-2021-40812 affects libgd. Severity is medium (CVSS 6.5). The GD Graphics Library (aka LibGD) through 2.3.2 has an out-of-bounds read because of the lack of certain gdGetBuf and gdPutBuf return value checks.

Q: How urgent is CVE-2021-40812?

Priority 42/100. No elevated risk signals yet.

This month

MEDIUM 6.5UPGRADE

CVE-2021-40812 is a medium-severity flaw (CVSS 6.5) affecting libgd. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The GD Graphics Library (aka LibGD) through 2.3.2 has an out-of-bounds read because of the lack of certain gdGetBuf and gdPutBuf return value checks.

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	6.5 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	1.7% (top 23%)
CISA exploited list	No
Weakness	CWE-125
Published	2021-09-08
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: libgd

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2021-09-08 21:15 UTCPublished CVE record published
2026-06-17 04:07 UTCUpdated Record last modified

libgd libgd UPGRADE

Affected: <= 2.3.2

Fixed in: newer than 2.3.2

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy libgd || rpm -q libgd || libgd --version

2. UPGRADE to newer than 2.3.2 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade libgd

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade libgd

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2021-40812?

libgd: upgrade to newer than 2.3.2. Exact commands for each OS are on this page.

Is CVE-2021-40812 being exploited?

CVE-2021-40812 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2021-40812 affect?

CVE-2021-40812 affects libgd. Severity is medium (CVSS 6.5). The GD Graphics Library (aka LibGD) through 2.3.2 has an out-of-bounds read because of the lack of certain gdGetBuf and gdPutBuf return value checks.

How urgent is CVE-2021-40812?

Priority 42/100. No elevated risk signals yet.

Related CVEs

CVE-2021-40145 HIGH 7.5 UPGRADE gdImageGd2Ptr in gd_gd2.c in the GD Graphics Library (aka LibGD) through 2.3.2 has a double free
CVE-2021-38115 MEDIUM 6.5 UPGRADE read_header_tga in gd_tga.c in the GD Graphics Library (aka LibGD) through 2.3.2 allows remote attackers to ca

References

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