Bug 2496135 (CVE-2026-58380)

Summary:	CVE-2026-58380 gimp: gimp: Stack buffer overflow in pnmscanner_gettoken()
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	rhel-process-autobot, watson-tool-maintainers
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	A flaw was found in GIMP's PNM file format parser. When parsing a specially crafted PNM file, the pnmscanner_gettoken() function writes a null terminator one byte past the end of a stack-allocated buffer due to an off-by-one error in the loop boundary check. This could lead to memory corruption, potentially resulting in denial of service or arbitrary code execution.	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-07-01 19:11:31 UTC

An off-by-one stack buffer overflow exists in GIMP's PNM file format parser. In pnmscanner_gettoken() in file-pnm.c, the loop condition ctr < bufsize allows ctr to reach bufsize (512), then buf[ctr] = '\0' writes one byte past the 512-byte stack buffer. The function is called from pnm_load_ascii() with a stack-allocated buf[BUFLEN] where BUFLEN = 512, with no extra room for the null terminator.

- Function: pnmscanner_gettoken()
- File: plug-ins/common/file-pnm.c:2103-2122
- Fix: https://gitlab.gnome.org/GNOME/gimp/-/commit/83699817
- Upstream issue: https://gitlab.gnome.org/GNOME/gimp/-/issues/16206
- Acknowledgment: bb1abu