DEBIAN-CVE-2026-48685

Source
https://security-tracker.debian.org/tracker/CVE-2026-48685
Import Source
https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-48685.json
JSON Data
https://api.osv.dev/v1/vulns/DEBIAN-CVE-2026-48685
Upstream
Published
2026-05-26T16:16:26Z
Modified
2026-09-14T17:03:42Z
Severity
  • 6.5 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
Summary
[none]
Details

FastNetMon Community Edition through 1.2.9 has out-of-bounds memory access because it incorrectly parses BGP path attributes with the extended length flag set. In src/bgp_protocol.hpp, the parse_raw_bgp_attribute() function correctly identifies when extended_length_bit is set and sets length_of_length_field to 2, but then reads only a single byte for the attribute value length (attribute_value_length = value[2] at line 173). Per RFC 4271 Section 4.3, when the Extended Length bit is set, the Attribute Length field is two octets and the value should be read as a 16-bit big-endian integer from value[2] and value[3]. As a result, any attribute longer than 255 bytes has its length silently truncated to the low byte (e.g., 300 bytes = 0x012C is read as 0x2C = 44 bytes). The remaining 256 bytes are then misinterpreted as subsequent attributes, causing cascading parse failures and potential out-of-bounds memory access.

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-2026-48685.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-2026-48685.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-2026-48685.json"