Description
A certain backport in the TCP Fast Open implementation for the Linux kernel before 3.18 does not properly maintain a count value, which allow local users to cause a denial of service (system crash) via the Fast Open feature, as demonstrated by visiting the chrome://flags/#enable-tcp-fast-open URL when using certain 3.10.x through 3.16.x kernel builds, including longterm-maintenance releases and ckt (aka Canonical Kernel Team) builds.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | linux | 3.16.7-ckt9-3 | — |
| Debian 13 | linux | 3.16.7-ckt9-3 | — |
| Debian 12 | linux | 3.16.7-ckt9-3 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 14.04 LTS | linux | 3.13.0-53.89 | USN-2620-1 |
| Ubuntu 14.04 LTS | linux-lts-utopic | 3.16.0-38.52~14.04.1 | USN-2615-1 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 | kernel-docs +1 | 3.12.43-52.6.2 | SUSE-SU-2015:1071-1 |
| SLES 12 | kernel-ec2 +4 | 3.12.43-52.6.1 | SUSE-SU-2015:1071-1 |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 12 | kernel-xen +3 | 3.12.43-52.6.1 | SUSE-SU-2015:1071-1 |
| SLE Live Patching 12 | kgraft-patch-SLE12_Update_5 | 1-2.3 | SUSE-SU-2015:1071-1 |
Advisories 3
- USN-2620-1 linux vulnerability Ubuntu Security Notices (USN) · Apr 22, 2026
- USN-2615-1 linux-lts-utopic vulnerabilities Ubuntu Security Notices (USN) · Feb 10, 2026
- SUSE-SU-2015:1071-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026