DEBIAN-CVE-2026-48691

Source
https://security-tracker.debian.org/tracker/CVE-2026-48691
Import Source
https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-48691.json
JSON Data
https://api.osv.dev/v1/vulns/DEBIAN-CVE-2026-48691
Upstream
Published
2026-05-26T17:16:53Z
Modified
2026-09-14T17:03:16Z
Severity
  • 9.8 (Critical) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
Summary
[none]
Details

FastNetMon Community Edition through 1.2.9 contains an integer overflow in the BGP AS_PATH attribute encoder. In src/bgp_protocol.hpp, the IPv4UnicastAnnounce::get_attributes() function computes attribute_length as 'sizeof(bgp_as_path_segment_element_t) + this->as_path_asns.size() * sizeof(uint32_t)' and stores it in a uint8_t field (line 600-605). Since uint8_t can only hold values 0-255, an AS_PATH containing more than 63 ASNs (2 + 64*4 = 258 > 255) causes silent truncation. The truncated length is used for buffer sizing, while the actual data written is the full untruncated amount, resulting in a heap buffer overflow. Similarly, the path_segment_length field at line 621 is also uint8_t, truncating with more than 255 ASNs.

References

Affected packages

Debian:12 / fastnetmon

Package

Name
fastnetmon
Purl
pkg:deb/debian/fastnetmon?arch=source&distro=bookworm

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

1.*
1.2.4-2
1.2.4-2+deb12u1
1.2.5-1
1.2.5-2~bpo12+1
1.2.5-2
1.2.6-1~bpo12+1
1.2.6-1
1.2.7-1~bpo12+1
1.2.7-1
1.2.8-1~bpo12+1
1.2.8-1
1.2.8+git20250911-1
1.2.8+git20250911-2
1.2.9-1

Ecosystem specific

{
    "urgency": "unimportant"
}

Database specific

source
"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-48691.json"

Debian:13 / fastnetmon

Package

Name
fastnetmon
Purl
pkg:deb/debian/fastnetmon?arch=source&distro=trixie

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
1.2.9-0+deb13u1

Affected versions

1.*
1.2.8-1
1.2.8+git20250911-1
1.2.8+git20250911-2

Ecosystem specific

{
    "urgency": "not yet assigned"
}

Database specific

source
"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-48691.json"

Debian:14 / fastnetmon

Package

Name
fastnetmon
Purl
pkg:deb/debian/fastnetmon?arch=source&distro=forky

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
1.2.9-1

Affected versions

1.*
1.2.8-1
1.2.8+git20250911-1
1.2.8+git20250911-2

Ecosystem specific

{
    "urgency": "unimportant"
}

Database specific

source
"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-48691.json"