Vulnerability in Simsong Tcpflow
CVE-2026-119600
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.8 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/simsong/tcpflow/issues/279 (issue-tracking)
- github.com/simsong/tcpflow/blob/tcpflow-1.6.1/src/tcpdemux.cpp (technical-description)
- github.com/simsong/tcpflow/blob/tcpflow-1.6.1/src/tcpdemux.cpp (technical-description)
- hackmd.io/@haindpwn/tcpflow-ip-payload-length-oob-read (third-party-advisory)
- github.com/simsong/tcpflow (product)
- www.vulncheck.com/advisories/tcpflow-through-1.6.1-out-of-bounds-read-via-tcp-d… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-119600?
- CVE-2026-119600 is a medium-severity vulnerability in Simsong Tcpflow, classified under Improper Handling of Length Parameter Inconsistency. CVSS score: 4.8/10. Published 2026-10-30.
- How severe is CVE-2026-119600?
- Medium severity. CVSS v3 base score is 4.8 out of 10.