CVE-2026-77652 (GCVE-0-2026-77652)
Vulnerability from cvelistv5 – Published: 2026-08-26 19:21 – Updated: 2026-08-26 19:21
VLAI
EPSS
VEX
Title
Dia: dia: heap buffer overflow in wpg colormap parser via out-of-bounds palette index
Summary
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).
Severity
7.8 (High)
CWE
- CWE-122 - Heap-based Buffer Overflow
Assigner
References
4 references
| URL | Tags |
|---|---|
| https://access.redhat.com/security/cve/CVE-2026-77652 | vdb-entryx_refsource_REDHAT |
| https://bugzilla.redhat.com/show_bug.cgi?id=2520884 | issue-trackingx_refsource_REDHAT |
| https://gitlab.gnome.org/GNOME/dia/-/blob/master/… | |
| https://gitlab.gnome.org/GNOME/dia/-/issues/580 |
Impacted products
Date Public
2026-08-21 00:00
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"redhat_vex": {
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"cve": "CVE-2026-77652",
"id": "CVE-2026-77652",
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"source": "Red Hat CSAF VEX",
"status": "final",
"title": "dia: dia: heap buffer overflow in WPG colormap parser via out-of-bounds palette index",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-77652.json",
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}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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