CVE-2026-77652
Publication date 26 August 2026
Last updated 2 September 2026
Ubuntu priority
Description
A heap-based buffer overflow vulnerability exists in the Dia diagram editor WPG file format importer. In plug-ins/wpg/wpg-import.c, the WPG import renderer allocates a fixed palette with: ren->pPal = g_new0(WPGColorRGB, 256); When handling a WPG_COLORMAP record, the parser reads a start index (i16) and number of colors (iNum16) from the file and reads palette data with: bRet &= (iNum16 == (int)fread(&ren->pPal[i16], sizeof(WPGColorRGB), iNum16, f)); The only bounds-related check is `if (i16 >= 0 && i16 <= iSize)`, where iSize is the WPG record size—not the palette capacity. There is no validation that i16 is less than 256 or that i16 + iNum16 does not exceed 256. A malicious WPG file can supply i16=256 and iNum16=264. That causes fread() to write 792 bytes starting at &pPal[256], while the palette buffer is only 768 bytes (256 entries × 3 bytes). This overflows into adjacent heap metadata and can crash Dia (SIGABRT / malloc corruption errors) or, depending on heap layout and exploit primitives, potentially lead to arbitrary code execution. Exploitation requires convincing a user to open a crafted WPG file via Dia's file dialog, command line, or file association. No special privileges are required to deliver the file to the victim. Affected component: WPG parser (plug-ins/wpg/wpg-import.c). Affected versions: all Dia versions containing this code path (reporter tested Dia 0.98+git20260221-1; issue present on upstream master as of 2026-08-21).
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| dia | 26.04 LTS resolute |
Needs evaluation
|
| 24.04 LTS noble |
Needs evaluation
|
|
| 22.04 LTS jammy |
Needs evaluation
|
|
| 20.04 LTS focal |
Needs evaluation
|
|
| 18.04 LTS bionic |
Needs evaluation
|
|
| 16.04 LTS xenial |
Needs evaluation
|
Severity score breakdown
CVSS version: CVSS v3.0
Base score
7.8 · High
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H