# CVE-2026-18303: GIMP TIF file parsing stack-based buffer overflow

Source: https://junglewise.ai/threats/cve-2026-18303-gimp-tif-file-parsing-stack-based-buffer-overflow  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-20. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-18303 · Severity: high · CVSS 7.8 · Published 2026-08-20

GIMP is a popular image editor used to create and manipulate digital images. This vulnerability exists in GIMP's handling of TIF image files and allows an attacker to execute arbitrary code on a user's computer by tricking them into opening a malicious image file. The attacker would have complete control over the affected system, potentially allowing theft of sensitive data or installation of malware.

Technologies: [Gimp](https://junglewise.ai/threats/technologies/gimp). Vendors: [Gimp](https://junglewise.ai/threats/vendors/gimp).

## Quick answers

**Is CVE-2026-18303 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-18303 being exploited in the wild.

**How severe is CVE-2026-18303?** High severity, with a CVSS score of 7.8, published 20 August 2026.

**Which products and versions are affected?** GIMP GIMP.

**Is there a fix for CVE-2026-18303?** A patch was published on 2026-07-29: GIMP patch released; see https://gitlab.gnome.org/GNOME/gimp/-/commit/5633b362026c6e5b2beb559a10cd76fa32a47592 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-18303 attacked?** It is attacked with local access, in a software library.

**Am I affected by CVE-2026-18303?** Check whether you run Gimp. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A stack-based buffer overflow vulnerability exists in GIMP's TIF file parser due to insufficient validation of user-supplied data length before copying to a stack buffer. The vulnerability is reachable when a user opens a crafted TIF file, either by visiting a malicious web page or directly opening a malicious file. Successful exploitation allows an attacker to execute arbitrary code in the context of the GIMP process with the privileges of the user running GIMP. GIMP has released a patch to address this issue. No active exploitation in the wild has been reported.

## Affected products

- GIMP GIMP

## Timeline

- 2026-04-17: disclosed: Vulnerability reported to vendor
- 2026-07-29: advisory: Coordinated public release of advisory (ZDI-26-456)
- 2026-07-29: patched: GIMP patch released; see https://gitlab.gnome.org/GNOME/gimp/-/commit/5633b362026c6e5b2beb559a10cd76fa32a47592

## References

- [https://gitlab.gnome.org/GNOME/gimp/-/commit/5633b362026c6e5b2beb559a10cd76fa32a47592](https://gitlab.gnome.org/GNOME/gimp/-/commit/5633b362026c6e5b2beb559a10cd76fa32a47592)
- [https://www.zerodayinitiative.com/advisories/ZDI-26-456/](https://www.zerodayinitiative.com/advisories/ZDI-26-456/)

## Related threats

- [GIMP use-after-free in XCF path loader](https://junglewise.ai/threats/cve-2026-112261-a-flaw-was-found-in-gimp-opening-a-crafted-xcf-that-selects-a)
- [GIMP use-after-free in XCF loader](https://junglewise.ai/threats/cve-2026-112258-a-flaw-was-found-in-gimp-the-xcf-loader-can-leave-a-dangling)
- [GIMP integer overflow in file-pvr plug-in](https://junglewise.ai/threats/cve-2026-62439-a-flaw-was-found-in-gimp-an-integer-overflow-occurs-in-the-file)
- [GIMP heap buffer overflow in raw data export](https://junglewise.ai/threats/cve-2026-106066-a-heap-based-buffer-overflow-was-found-in-gimp-s-raw-data-export)
- [GIMP heap buffer overflow in GIF export](https://junglewise.ai/threats/cve-2026-106064-a-heap-based-buffer-overflow-was-found-in-gimp-s-gif-export-plug)