Vulnerability · Published Oct 30, 2026 · Assigned by VulnCheck
CVE-2026-119600tcpflow through 1.6.1 Out-of-Bounds Read via TCP Demultiplexer Payload Length
Medium 4.8
In plain English
A medium-severity security flaw in tcpflow from simsong. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 31% of all known vulnerabilities).
Severity (CVSS 3.1)4.8Medium
Exploit odds (30 days)0.4%top 68.6% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
tcpflow through 1.6.1 contains an out-of-bounds read vulnerability that allows unauthenticated attackers to read process memory by sending packets with forged IP payload lengths. Attackers can inject crafted IPv4 or IPv6 TCP packets into captured traffic or pcap files to leak adjacent memory into reconstructed flow files or crash tcpflow.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | tcpflow | no fix listed | DEBIAN-CVE-2026-119600 |
| Debian:13 | tcpflow | no fix listed | DEBIAN-CVE-2026-119600 |
| Debian:14 | tcpflow | no fix listed | DEBIAN-CVE-2026-119600 |
| Ubuntu:22.04:LTS | tcpflow | no fix listed | UBUNTU-CVE-2026-119600 |
| Ubuntu:24.04:LTS | tcpflow | no fix listed | UBUNTU-CVE-2026-119600 |
| Ubuntu:26.04:LTS | tcpflow | no fix listed | UBUNTU-CVE-2026-119600 |
| Ubuntu:26.10 | tcpflow | no fix listed | UBUNTU-CVE-2026-119600 |
Affected products (as reported)
Weakness: CWE-130 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L
References
- https://github.com/simsong/tcpflow/issues/279 issue-tracking
- https://github.com/simsong/tcpflow/blob/tcpflow-1.6.1/src/tcpdemux.cpp#L781 technical-description
- https://github.com/simsong/tcpflow/blob/tcpflow-1.6.1/src/tcpdemux.cpp#L747 technical-description
- https://hackmd.io/@haindpwn/tcpflow-ip-payload-length-oob-read third-party-advisory
- https://github.com/simsong/tcpflow product
- VulnCheck Advisory: tcpflow through 1.6.1 Out-of-Bounds Read via TCP Demultiplexer Payload Length third-party-advisory