Executive brief
A vulnerability has been identified in giflib, a widely used library for processing GIF images. An attacker can exploit this flaw by providing a specially crafted image file, which could cause applications using the library to crash or behave unexpectedly. This may lead to a disruption of services that rely on image processing, such as web servers or document viewers.
Technical details
A buffer overflow vulnerability exists in giflib version 5.2.2 within the EGifGCBToExtension and EGifGCBToSavedExtension functions in egif_lib.c. The issue stems from the library overwriting an existing Graphic Control Extension (GCE) block without properly validating the allocated size of the destination buffer. A remote, unauthenticated attacker can exploit this by providing a malformed GIF, leading to an out-of-bounds write. This can result in a denial of service (application crash) or potentially limited data corruption. While a fix was reported to be in the pipeline by upstream maintainers, it was not yet fully resolved at the time of the advisory.
Affected products
- giflib project giflib 5.2.2
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat Enterprise Linux 10
Timeline
- 2026-03-18: disclosed: Initial disclosure of CVE-2026-26740
- 2026-03-18: advisory: NVD publication date