Description
Integer signedness error in GD Graphics Library 2.1.1 (aka libgd or libgd2) allows remote attackers to cause a denial of service (crash) or potentially execute arbitrary code via crafted compressed gd2 data, which triggers a heap-based buffer overflow.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | libgd2 | 2.1.1-4.1 | — |
| Debian 13 | libgd2 | 2.1.1-4.1 | — |
| Debian 12 | libgd2 | 2.1.1-4.1 | — |
| Debian 8 | libgd2 | 2.1.0-5+deb8u1 | DSA-3556-1 |
| Debian 8 | php5 | 5.6.22+dfsg-0+deb8u1 | DSA-3602-1 |
| Debian 7 | libgd2 | 2.0.36~rc1~dfsg-6.1+deb7u2 | DSA-3556-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | libgd2 | 2.1.1-4ubuntu0.16.04.1 | USN-2987-1 |
| Ubuntu 14.04 LTS | libgd2 | 2.1.0-3ubuntu0.1 | USN-2987-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 2 | rh-php56 +2 | 2.3-1.el6 | RHSA-2016:2750 |
| RHEL 2 | rh-php56-php +27 | 5.6.25-1.el6 | RHSA-2016:2750 |
| RHEL 2 | rh-php56-php-pear | 1:1.9.5-4.el6 | RHSA-2016:2750 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.4 | gd | 2.2.1-r0 | — |
| Alpine v3.3 | gd | 2.2.1-r2 | — |
| Alpine v3.2 | gd | 2.2.1-r2 | — |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.
Exploit-DB 1
- libgd 2.1.1 - Signedness Heap Overflow EDB-39736 · remote · Apr 26, 2016
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 4
- RHSA-2016:2750 Red Hat Security Advisory: rh-php56 security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Aug 5, 2026
- USN-2987-1 libgd2 vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- DSA-3556-1 libgd2 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-3602-1 php5 - security update Debian Security (DSA / DLA) · Mar 9, 2026
References
- DSA-3556 vendor-advisory
- 39736 exploit
- GLSA-201611-22 vendor-advisory
- 87087 vdb-entry
- RHSA-2016:2750 vendor-advisory
- 20160421 CVE-2016-3074: libgd: signedness vulnerability mailing-list
- DSA-3602 vendor-advisory
- FEDORA-2016-0c57b12c7b vendor-advisory
- 1035659 vdb-entry
- GLSA-201607-04 vendor-advisory
- USN-2987-1 vendor-advisory
- SSA:2016-120-02 vendor-advisory
- http://packetstormsecurity.com/files/136757/libgd-2.1.1-Signedness.html
- https://h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05240731
- 20160421 CVE-2016-3074: libgd: signedness vulnerability mailing-list
- FEDORA-2016-5f91f43826 vendor-advisory
- openSUSE-SU-2016:1274 vendor-advisory
- https://github.com/libgd/libgd/commit/2bb97f407c1145c850416a3bfbcc8cf124e68a19