CVE-2026-48682_CVE-2026-48682

5.9 / 10

MEDIUM

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Description

FastNetMon Community Edition through 1.2.9 contains an out-of-bounds read in the IPv4 packet parser. In src/simple_packet_parser_ng.cpp, after validating that the packet contains at least sizeof(ipv4_header_t) bytes (20 bytes), the code advances the local_pointer by '4 * ipv4_header->get_ihl()' (line 164) without validating that (a) IHL >= 5 (the minimum valid value per RFC 791), or (b) 4 * IHL bytes are actually available in the packet. The IHL field is 4 bits, allowing values 0-15, so the advance can be 0-60 bytes. An IHL value of 15 with only 20 bytes validated causes a 40-byte over-read. An IHL of 0-4 causes the pointer to not advance past the IP header, resulting in the TCP/UDP header being parsed from IP header data (type confusion). This vulnerability is reachable via any packet capture interface.

Basic Information

ID CVE-2026-48682

Source mitre

Published Jun 2, 2026 at 00:00

Modified Jun 4, 2026 at 13:21

Affected Product

Vendor n/a

Product n/a

Version n/a

Affected Versions n/a n/a n/a

CWE Classification

CWE-125

References

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    "published": "2026-06-02T00:00:00.000Z",
    "modified": "2026-06-04T13:21:59.532Z",
    "type": "cve",
    "title": "CVE-2026-48682",
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    "references": "https://github.com/pavel-odintsov/fastnetmon\nhttps://github.com/pavel-odintsov/fastnetmon/blob/master/src/simple_packet_parser_ng.cpp\nhttps://lorikeetsecurity.com/blog/fastnetmon-cve-2026-48682-ipv4-parser-oob",
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