Vulnerability Description
Netty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Final and 4.2.15.Final, netty_unix_socket_recvFd sets msg_control to `char control[CMSG_SPACE(sizeof(int))]` (line 940) — 24 bytes on 64-bit Linux. A peer-sent SCM_RIGHTS cmsg carrying two ints has cmsg_len = CMSG_LEN(8) = 24, which fits exactly with no MSG_CTRUNC, so the kernel installs both fds in the receiving process. The subsequent check `cmsg->cmsg_len == CMSG_LEN(sizeof(int))` (line 972, expected 20) fails, the branch that would read the fd is skipped, and neither installed fd is closed. The for(;;) loop calls recvmsg again (non-blocking → EAGAIN → Java maps to 0 → read loop exits normally), leaving two leaked fds per message. There is no MSG_CTRUNC handling. Reachable via Epoll/KQueue DomainSocketChannel when the application opts into DomainSocketReadMode.FILE_DESCRIPTORS (non-default). Versions 4.1.135.Final and 4.2.15.Final patch the issue.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Netty | Netty | < 4.1.135 |
Related Weaknesses (CWE)
References
- https://github.com/netty/netty/releases/tag/netty-4.1.135.FinalRelease Notes
- https://github.com/netty/netty/releases/tag/netty-4.2.15.FinalRelease Notes
- https://github.com/netty/netty/security/advisories/GHSA-w573-9ffj-6ff9Vendor Advisory
FAQ
What is CVE-2026-45536?
CVE-2026-45536 is a vulnerability with a CVSS score of 4.0 (MEDIUM). Netty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Final and 4.2.15.Final, netty_unix_socket_recvFd sets msg_control to `char control[C...
How severe is CVE-2026-45536?
CVE-2026-45536 has been rated MEDIUM with a CVSS base score of 4.0/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-45536?
Check the references section above for vendor advisories and patch information. Affected products include: Netty Netty.