Dia: dia: heap buffer overflow in wpg colormap parser via out-of-bounds palette index
Summary
| CVE | CVE-2026-77652 |
|---|---|
| State | PUBLISHED |
| Assigner | fedora |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-08-26 20:18:02 UTC |
| Updated | 2026-08-26 20:18:02 UTC |
| 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). |
Risk And Classification
Primary CVSS: v3.1 7.8 HIGH from [email protected]
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Problem Types: CWE-122 | CWE-122 Heap-based Buffer Overflow
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 7.8 | HIGH | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
| 3.1 | CNA | CVSS | 7.8 | HIGH | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
CVSS v3.1 Breakdown
Attack Vector
LocalAttack Complexity
LowPrivileges Required
NoneUser Interaction
RequiredScope
UnchangedConfidentiality
HighIntegrity
HighAvailability
HighCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Vendor Declared Affected Products
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| access.redhat.com/security/cve/CVE-2026-77652 | [email protected] | access.redhat.com | |
| gitlab.gnome.org/GNOME/dia/-/issues/580 | [email protected] | gitlab.gnome.org | |
| gitlab.gnome.org/GNOME/dia/-/blob/master/plug-ins/wpg/wpg-import.c | [email protected] | gitlab.gnome.org | |
| bugzilla.redhat.com/show_bug.cgi | [email protected] | bugzilla.redhat.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Red Hat would like to thank Robin "drzobin" Larsson for reporting this issue. (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-08-21T03:45:55.032Z | Reported to Red Hat. |
| CNA | 2026-08-21T00:00:00.000Z | Made public. |
There are currently no legacy QID mappings associated with this CVE.