Out-of-bounds write in Tcpreplay - #VU139346
Published: July 24, 2026
Vulnerability identifier: #VU139346
CSH Severity: Low
CVSS v4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-787
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to out-of-bounds write in the tcprewrite fragroute rules parser in mod_open() when parsing an empty or comment-only fragroute rules file. A local user can provide a crafted fragroute rules file to cause a denial of service.
Exploitation requires tcprewrite to be built with libdnet/fragroute support and invoked with the --fragroute option. The write occurs during startup before any packet is processed.
Affected software
Tcpreplay
Remediation
Install security update from vendor's website.
Tcpreplay - addressed in versions 4.5.5, 4.6.0 beta2