DEBIAN-CVE-2026-77658
A stack-based buffer overflow vulnerability exists in the Dia diagram editor when processing Network Bus objects from Dia XML project files. In objects/network/bus.c, bus_load() reads the number of bus handles from the file attribute "bus_handles" using attribute_num_data() without validating an upper bound: bus->num_handles = attribute_num_data(attr); When a bus handle is subsequently moved, bus_handle_moved() allocates two temporary arrays on the stack: parallel = (real *)g_alloca(num_handles * sizeof(real)); perp = (real *)g_alloca(num_handles * sizeof(real)); Because num_handles is fully attacker-controlled via the project file, sufficiently large values (for example 262144 or higher) cause g_alloca() to consume more stack space than the default thread stack limit (typically 8 MB on Linux), resulting in stack overflow, SIGSEGV, and potential stack frame / return-address corruption. An attacker can embed a Bus object with an excessive bus_handles count in a malicious .dia file. Exploitation requires the victim to open the file in Dia (file dialog, command line, or file association) and trigger handle manipulation (moving a bus handle), which exercises the vulnerable code path. The identical g_alloca pattern is present in objects/Misc/tree.c (copied from bus.c) and is likely vulnerable to the same class of attack via Tree objects. Affected versions: Dia 0.98.0 and earlier versions containing this code; issue confirmed on upstream master as of 2026-08-21. Upstream report: ht
DEBIAN-CVE-2026-77658
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: osv:DEBIAN-CVE-2026-77658
dia
Source reference: /affected/0/package/name
- Affected versions
- 0.97.3+git20220525-5
Source reference:
/affected/0/versions0.98+git20240130-1Source reference:
/affected/0/versions0.98+git20240528-1Source reference:
/affected/0/versions0.98+git20240814-1Source reference:
/affected/0/versions0.98+git20250126-1Source reference:
/affected/0/versions0.98+git20250126-2Source reference:
/affected/0/versions0.98+git20250827-1Source reference:
/affected/0/versions0.98+git20250827-2Source reference:
/affected/0/versions0.98+git20260221-1Source reference:
/affected/0/versions0.98+git20260221-2Source reference:
/affected/0/versions0.98+git20260221-3Source reference:
/affected/0/versions - Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
dia
Source reference: /affected/1/package/name
- Affected versions
- 0.98+git20250126-2
Source reference:
/affected/1/versions0.98+git20250827-1Source reference:
/affected/1/versions0.98+git20250827-2Source reference:
/affected/1/versions0.98+git20260221-1Source reference:
/affected/1/versions0.98+git20260221-2Source reference:
/affected/1/versions0.98+git20260221-3Source reference:
/affected/1/versions - Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
dia
Source reference: /affected/2/package/name
- Affected versions
- 0.98+git20250126-2
Source reference:
/affected/2/versions0.98+git20250827-1Source reference:
/affected/2/versions0.98+git20250827-2Source reference:
/affected/2/versions0.98+git20260221-1Source reference:
/affected/2/versions0.98+git20260221-2Source reference:
/affected/2/versions0.98+git20260221-3Source reference:
/affected/2/versions - Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "dia",
"purl": "pkg:deb/debian/dia?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"versions": [
"0.97.3+git20220525-5",
"0.98+git20240130-1",
"0.98+git20240528-1",
"0.98+git20240814-1",
"0.98+git20250126-1",
"0.98+git20250126-2",
"0.98+git20250827-1",
"0.98+git20250827-2",
"0.98+git20260221-1",
"0.98+git20260221-2",
"0.98+git20260221-3"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-77658.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "dia",
"purl": "pkg:deb/debian/dia?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"versions": [
"0.98+git20250126-2",
"0.98+git20250827-1",
"0.98+git20250827-2",
"0.98+git20260221-1",
"0.98+git20260221-2",
"0.98+git20260221-3"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-77658.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "dia",
"purl": "pkg:deb/debian/dia?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"versions": [
"0.98+git20250126-2",
"0.98+git20250827-1",
"0.98+git20250827-2",
"0.98+git20260221-1",
"0.98+git20260221-2",
"0.98+git20260221-3"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-77658.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
]Publisher severity
No explicit severity was provided.
- Event
- #58347 · Revision 1
- Added to Heist Feed
- Publisher date