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DEBIAN-CVE-2026-48685

Type: advisorySource: OSV1 source record

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.

Announced Source revision 1
Original source ↗

DEBIAN-CVE-2026-48685

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-2026-48685

fastnetmon

Source reference: /affected/0/package/name

Affected versions
1.2.4-2

Source reference: /affected/0/versions

1.2.4-2+deb12u1

Source reference: /affected/0/versions

1.2.5-1

Source reference: /affected/0/versions

1.2.5-2

Source reference: /affected/0/versions

1.2.5-2~bpo12+1

Source reference: /affected/0/versions

1.2.6-1

Source reference: /affected/0/versions

1.2.6-1~bpo12+1

Source reference: /affected/0/versions

1.2.7-1

Source reference: /affected/0/versions

1.2.7-1~bpo12+1

Source reference: /affected/0/versions

1.2.8+git20250911-1

Source reference: /affected/0/versions

1.2.8+git20250911-2

Source reference: /affected/0/versions

1.2.8-1

Source reference: /affected/0/versions

1.2.8-1~bpo12+1

Source reference: /affected/0/versions

1.2.9-1

Source reference: /affected/0/versions

Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

fastnetmon

Source reference: /affected/1/package/name

Affected versions
1.2.8+git20250911-1

Source reference: /affected/1/versions

1.2.8+git20250911-2

Source reference: /affected/1/versions

1.2.8-1

Source reference: /affected/1/versions

Fixed versions
1.2.9-0+deb13u1

Source reference: /affected/1/ranges

Prerequisites
Not stated in this record

fastnetmon

Source reference: /affected/2/package/name

Affected versions
1.2.8+git20250911-1

Source reference: /affected/2/versions

1.2.8+git20250911-2

Source reference: /affected/2/versions

1.2.8-1

Source reference: /affected/2/versions

Fixed versions
1.2.9-1

Source reference: /affected/2/ranges

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": "fastnetmon",
      "purl": "pkg:deb/debian/fastnetmon?arch=source&distro=bookworm",
      "ecosystem": "Debian:12"
    },
    "versions": [
      "1.2.4-2",
      "1.2.4-2+deb12u1",
      "1.2.5-1",
      "1.2.5-2",
      "1.2.5-2~bpo12+1",
      "1.2.6-1",
      "1.2.6-1~bpo12+1",
      "1.2.7-1",
      "1.2.7-1~bpo12+1",
      "1.2.8+git20250911-1",
      "1.2.8+git20250911-2",
      "1.2.8-1",
      "1.2.8-1~bpo12+1",
      "1.2.9-1"
    ],
    "database_specific": {
      "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-48685.json"
    },
    "ecosystem_specific": {
      "urgency": "unimportant"
    }
  },
  {
    "ranges": [
      {
        "type": "ECOSYSTEM",
        "events": [
          {
            "introduced": "0"
          },
          {
            "fixed": "1.2.9-0+deb13u1"
          }
        ]
      }
    ],
    "package": {
      "name": "fastnetmon",
      "purl": "pkg:deb/debian/fastnetmon?arch=source&distro=trixie",
      "ecosystem": "Debian:13"
    },
    "versions": [
      "1.2.8+git20250911-1",
      "1.2.8+git20250911-2",
      "1.2.8-1"
    ],
    "database_specific": {
      "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-48685.json"
    },
    "ecosystem_specific": {
      "urgency": "not yet assigned"
    }
  },
  {
    "ranges": [
      {
        "type": "ECOSYSTEM",
        "events": [
          {
            "introduced": "0"
          },
          {
            "fixed": "1.2.9-1"
          }
        ]
      }
    ],
    "package": {
      "name": "fastnetmon",
      "purl": "pkg:deb/debian/fastnetmon?arch=source&distro=forky",
      "ecosystem": "Debian:14"
    },
    "versions": [
      "1.2.8+git20250911-1",
      "1.2.8+git20250911-2",
      "1.2.8-1"
    ],
    "database_specific": {
      "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-48685.json"
    },
    "ecosystem_specific": {
      "urgency": "unimportant"
    }
  }
]

Publisher severity

No explicit severity was provided.

Event
#57239 · Revision 1
Added to Heist Feed
Publisher date
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