CVE-2025-24934
SO_REUSEPORT_LB breaks connect(2) for UDP sockets
Software which sets SO_REUSEPORT_LB on a socket and then connects it to a host will not directly observe any problems. However, due to its membership in a load-balancing group, that socket will receive packets originating from any host. This breaks the contract of the connect(2) and implied connect via sendto(2), and may leave the application vulnerable to spoofing attacks.
The kernel failed to check the connection state of sockets when adding them to load-balancing groups. Furthermore, when looking up the destination socket for an incoming packet, the kernel will match a socket belonging to a load-balancing group even if it is connected, in violation of the contract that connected sockets are only supposed to receive packets originating from the connected host.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
SO_REUSEPORT_LB breaks connect(2) for UDP sockets
Software which sets SO_REUSEPORT_LB on a socket and then connects it to a host will not directly observe any problems. However, due to its membership in a load-balancing group, that socket will receive packets originating from any host. This breaks the contract of the connect(2) and implied connect via sendto(2), and may leave the application vulnerable to spoofing attacks.
The kernel failed to check the connection state of sockets when adding them to load-balancing groups. Furthermore, when looking up the destination socket for an incoming packet, the kernel will match a socket belonging to a load-balancing group even if it is connected, in violation of the contract that connected sockets are only supposed to receive packets originating from the connected host.
- Record
CVE-2025-24934- CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N - Weakness
- CWE-488
- Updated
- 2026-11-02
EUVDEUVD-2025-35613
Software which sets SO_REUSEPORT_LB on a socket and then connects it to a host will not directly observe any problems. However, due to its membership in a load-balancing group, that socket will receive packets originating from any host. This breaks the contract of the connect(2) and implied connect via sendto(2), and may leave the application vulnerable to spoofing attacks.
The kernel failed to check the connection state of sockets when adding them to load-balancing groups. Furthermore, when looking up the destination socket for an incoming packet, the kernel will match a socket belonging to a load-balancing group even if it is connected, in violation of the contract that connected sockets are only supposed to receive packets originating from the connected host.
- Record
EUVD-2025-35613- CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-h546-6x4h-w6q7
Software which sets SO_REUSEPORT_LB on a socket and then connects it to a host will not directly...
Software which sets SO_REUSEPORT_LB on a socket and then connects it to a host will not directly observe any problems. However, due to its membership in a load-balancing group, that socket will receive packets originating from any host. This breaks the contract of the connect(2) and implied connect via sendto(2), and may leave the application vulnerable to spoofing attacks.
The kernel failed to check the connection state of sockets when adding them to load-balancing groups. Furthermore, when looking up the destination socket for an incoming packet, the kernel will match a socket belonging to a load-balancing group even if it is connected, in violation of the contract that connected sockets are only supposed to receive packets originating from the connected host.
- Record
GHSA-h546-6x4h-w6q7- CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N - Weakness
- CWE-488
- Updated
- 2026-11-02
NVD
Software which sets SO_REUSEPORT_LB on a socket and then connects it to a host will not directly observe any problems. However, due to its membership in a load-balancing group, that socket will receive packets originating from any host. This breaks the contract of the connect(2) and implied connect via sendto(2), and may leave the application vulnerable to spoofing attacks.
The kernel failed to check the connection state of sockets when adding them to load-balancing groups. Furthermore, when looking up the destination socket for an incoming packet, the kernel will match a socket belonging to a load-balancing group even if it is connected, in violation of the contract that connected sockets are only supposed to receive packets originating from the connected host.
- Record
CVE-2025-24934- CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N - Weakness
- CWE-488
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2025-24934 is a medium vulnerability (CVSS 5.4) in Freebsd, published October 22, 2025. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.21%, the 11th percentile. No source names a fixed version.