Description
In the Linux kernel, the following vulnerability has been resolved:
tls: make sure to abort the stream if headers are bogus
Normally we wait for the socket to buffer up the whole record
before we service it. If the socket has a tiny buffer, however,
we read out the data sooner, to prevent connection stalls.
Make sure that we abort the connection when we find out late
that the record is actually invalid. Retrying the parsing is
fine in itself but since we copy some more data each time
before we parse we can overflow the allocated skb space.
Constructing a scenario in which we're under pressure without
enough data in the socket to parse the length upfront is quite
hard. syzbot figured out a way to do this by serving us the header
in small OOB sends, and then filling in the recvbuf with a large
normal send.
Make sure that tls_rx_msg_size() aborts strp, if we reach
an invalid record there's really no way to recover.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 6.0 | 6.1.154 |
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 | 6.16.9-1 | — |
| Debian 13 | linux | 6.12.57-1 | — |
| Debian 12 | linux | 6.1.158-1 | DSA-6053-1 |
| Debian 11 | linux-6.1 | 6.1.158-1~deb11u1 | DLA-4379-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Nvidia-BlueField 24.04 LTS | linux-bluefield | 6.8.0-1016.20 | — |
| Ubuntu 25.10 | linux-azure-fde | No fix yet | — |
| Ubuntu 24.04 LTS | linux | 6.8.0-100.100 | USN-8028-1 |
| Ubuntu 24.04 LTS | linux-aws +1 | 6.8.0-1046.49 | USN-8028-5 |
| Ubuntu 24.04 LTS | linux-aws-6.14 | 6.14.0-1018.18~24.04.1 | USN-7921-1 |
| Ubuntu 24.04 LTS | linux-azure | 6.8.0-1046.52 | USN-8074-1 |
| Ubuntu 24.04 LTS | linux-azure-6.14 | 6.14.0-1017.17~24.04.1 | USN-7934-1 |
| Ubuntu 24.04 LTS | linux-azure-fde | 6.8.0-1046.53 | — |
| Ubuntu 24.04 LTS | linux-azure-nvidia | 6.8.0-1039.42 | — |
| Ubuntu 24.04 LTS | linux-gcp | 6.8.0-1047.50 | USN-8031-3 |
| Ubuntu 24.04 LTS | linux-gke | 6.8.0-1043.48 | USN-8031-3 |
| Ubuntu 24.04 LTS | linux-gkeop | 6.8.0-1030.33 | USN-8028-5 |
| Ubuntu 24.04 LTS | linux-hwe-6.14 | 6.14.0-37.37~24.04.1 | USN-7921-1 |
| Ubuntu 24.04 LTS | linux-ibm | 6.8.0-1044.44 | USN-8028-8 |
| Ubuntu 24.04 LTS | linux-intel +14 | No fix yet | — |
| Ubuntu 24.04 LTS | linux-lowlatency | 6.8.0-100.100.1 | USN-8052-1 |
| Ubuntu 24.04 LTS | linux-nvidia-lowlatency | 6.8.0-1046.49.1 | USN-8028-7 |
| Ubuntu 24.04 LTS | linux-nvidia-tegra | 6.8.0-1020.20 | — |
| Ubuntu 24.04 LTS | linux-oem-6.14 | 6.14.0-1017.17 | USN-7936-1 |
| Ubuntu 24.04 LTS | linux-oracle | 6.8.0-1043.44 | USN-8028-5 |
| Ubuntu 24.04 LTS | linux-raspi | 6.8.0-1047.51 | USN-8028-1 |
| Ubuntu 24.04 LTS | linux-riscv-6.14 | 6.14.0-37.37.1~24.04.1 | — |
| Ubuntu 24.04 LTS | linux-xilinx | 6.8.0-1023.24 | USN-8052-2 |
| Ubuntu 22.04 LTS | linux-aws-6.8 +1 | 6.8.0-1046.49~22.04.1 | USN-8028-5 |
| Ubuntu 22.04 LTS | linux-azure-6.8 | 6.8.0-1051.57~22.04.1 | USN-8126-1 |
| Ubuntu 22.04 LTS | linux-azure-fde-6.8 | 6.8.0-1046.53~22.04.1 | — |
| Ubuntu 22.04 LTS | linux-gcp-6.8 | 6.8.0-1047.50~22.04.2 | USN-8031-1 |
| Ubuntu 22.04 LTS | linux-hwe-6.8 +1 | 6.8.0-100.100~22.04.1 | USN-8028-6 |
| Ubuntu 22.04 LTS | linux-ibm-6.8 | 6.8.0-1044.44~22.04.1 | USN-8028-8 |
| Ubuntu 22.04 LTS | linux-lowlatency-hwe-6.8 | 6.8.0-100.100.1~22.04.1 | USN-8028-6 |
| Ubuntu 22.04 LTS | linux-oracle-6.8 | 6.8.0-1043.44~22.04.1 | USN-8028-5 |
| Ubuntu 22.04 LTS | linux-riscv +32 | No fix yet | — |
| Ubuntu 20.04 LTS | linux-gke +28 | No fix yet | — |
Show 5 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | linux-gcp +14 | No fix yet | — |
| Ubuntu 16.04 LTS | linux-hwe-edge | No fix yet | — |
| Ubuntu Pro Realtime 24.04 LTS | linux-raspi-realtime | 6.8.0-2037.38 | USN-8028-3 |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime | 6.8.1-1041.42 | USN-8028-3 |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime-6.14 | 6.14.0-1017.17~24.04.1 | USN-7921-2 |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime-6.8 | 6.8.1-1041.42~22.04.1 | USN-8028-2 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-aws-fips | 6.8.0-1046.49+fips1 | USN-8028-4 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-azure-fips | 6.8.0-1046.52+fips1 | USN-8074-2 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-fips | 6.8.0-100.100+fips1 | USN-8028-4 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-gcp-fips | 6.8.0-1047.50+fips1 | USN-8031-2 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10 | rv +76 | 6.12.0-124.11.1.el10_1 | RHSA-2025:21463 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | kernel-64kb +6 | 6.4.0-150700.53.22.1 | SUSE-SU-2025:4057-1 |
| SLES 15 SP7 | kernel-azure +2 | 6.4.0-150700.20.18.1 | SUSE-SU-2025:4132-1 |
| SLES 15 SP7 | kernel-default-base | 6.4.0-150700.53.22.1.150700.17.15.1 | SUSE-SU-2025:4057-1 |
| SLES 15 SP6 | kernel-64kb +6 | 6.4.0-150600.23.78.1 | SUSE-SU-2025:4140-1 |
| SLES 15 SP6 | kernel-azure +2 | 6.4.0-150600.8.55.1 | SUSE-SU-2025:4128-1 |
| SLES 15 SP6 | kernel-default-base | 6.4.0-150600.23.78.1.150600.12.34.2 | SUSE-SU-2025:4140-1 |
Show 9 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | kernel-64kb +7 | 6.12.0-160000.6.1 | SUSE-SU-2025:21139-1 |
| SLES for SAP 16.0 | kernel-default-base | 6.12.0-160000.6.1.160000.2.4 | SUSE-SU-2025:21139-1 |
| SLES 16.0 | kernel-64kb +7 | 6.12.0-160000.6.1 | SUSE-SU-2025:21179-1, SUSE-SU-2025:21139-1 |
| SLES 16.0 | kernel-default-base | 6.12.0-160000.6.1.160000.2.4 | SUSE-SU-2025:21139-1 |
| SLE Micro 6.2 | kernel-default-base | 6.12.0-160000.6.1.160000.2.4 | SUSE-SU-2025:21074-1 |
| SLE Micro 6.2 | kernel-rt +5 | 6.12.0-160000.6.1 | SUSE-SU-2026:20560-1, SUSE-SU-2025:21074-1 |
| SLE Micro 6.1 | kernel-default-base | 6.4.0-36.1.21.13 | SUSE-SU-2025:21056-1 |
| SLE Micro 6.1 | kernel-rt +1 | 6.4.0-38.1 | SUSE-SU-2025:21064-1 |
| SLE Micro 6.1 | kernel-source +2 | 6.4.0-36.1 | SUSE-SU-2025:21056-1 |
| SLE Micro 6.0 | kernel-default-base | 6.4.0-36.1.21.13 | SUSE-SU-2025:21040-1 |
| SLE Micro 6.0 | kernel-rt +1 | 6.4.0-38.1 | SUSE-SU-2025:21052-1 |
| SLE Micro 6.0 | kernel-source +2 | 6.4.0-36.1 | SUSE-SU-2025:21040-1 |
| SLE Live Patching 15 SP7 | kernel-default | 6.4.0-150700.53.22.1 | SUSE-SU-2025:4057-1 |
| SLE Live Patching 15 SP7 | kernel-livepatch-SLE15-SP7-RT_Update_6 | 1-150700.1.3.1 | SUSE-SU-2025:4141-1 |
| SLE Live Patching 15 SP7 | kernel-livepatch-SLE15-SP7_Update_6 | 1-150700.15.3.1 | SUSE-SU-2025:4057-1 |
| SLE Live Patching 15 SP6 | kernel-default | 6.4.0-150600.23.78.1 | SUSE-SU-2025:4140-1 |
| SLE Live Patching 15 SP6 | kernel-livepatch-SLE15-SP6-RT_Update_17 | 1-150600.1.3.1 | SUSE-SU-2025:4301-1 |
| SLE Live Patching 15 SP6 | kernel-livepatch-SLE15-SP6_Update_17 | 1-150600.13.5.1 | SUSE-SU-2025:4140-1 |
| SUSE Real Time Module 15 SP7 | kernel-rt +2 | 6.4.0-150700.7.22.1 | SUSE-SU-2025:4141-1 |
| SUSE Real Time Module 15 SP6 | kernel-rt +3 | 6.4.0-150600.10.58.1 | SUSE-SU-2025:4301-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 16.0 | kernel-default-base | 6.12.0-160000.6.1.160000.2.4 | openSUSE-SU-2025:20081-1 |
| openSUSE Leap 16.0 | kernel-rt +10 | 6.12.0-160000.6.1 | openSUSE-SU-2025:20081-1 |
| openSUSE Leap 15.6 | dtb-aarch64 +10 | 6.4.0-150600.23.78.1 | SUSE-SU-2025:4140-1 |
| openSUSE Leap 15.6 | kernel-azure +2 | 6.4.0-150600.8.55.1 | SUSE-SU-2025:4128-1 |
| openSUSE Leap 15.6 | kernel-default-base | 6.4.0-150600.23.78.1.150600.12.34.2 | SUSE-SU-2025:4140-1 |
| openSUSE Leap 15.6 | kernel-rt +3 | 6.4.0-150600.10.58.1 | SUSE-SU-2025:4301-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | kernel-livepatch-6.12.53-69.119 +1 | 1:1.0-0.amzn2023 | ALAS2023-2025-1254, ALAS2023-2025-1223 |
| Amazon Linux 2023 | perf +14 | 1:6.1.155-176.282.amzn2023 | ALAS2023-2025-1223 |
| Amazon Linux 2023 | perf6.12 +14 | 1:6.12.53-69.119.amzn2023 | ALAS2023-2025-1254 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | kernel | 6.6.112.1-1 | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 10 | rv +29 | 6.12.0-124.13.1.el10_1 | ELSA-2025-21463 |
| Oracle Linux 9 | kernel-uek +34 | 6.12.0-104.43.4.3.el10uek | ELSA-2025-25754, ELSA-2025-20719 |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.
GitHub 1 repository
-
farazsth98/exploit-CVE-2025-39946 ★ 37 · Oct 4, 2025
Exploit for CVE-2025-39946, a bug in the Linux kernel's net/tls subsystem.
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 46
- WID-SEC-2025-2194 Linux Kernel: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 12, 2026
- USN-8028-5 linux-aws, linux-aws-6.8, linux-gkeop, linux-nvidia, linux-nvidia-6.8, linux-oracle, linux-oracle-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8126-1 linux-azure-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8028-8 linux-ibm, linux-ibm-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8028-6 linux-hwe-6.8, linux-lowlatency-hwe-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8052-1 linux-lowlatency vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8052-2 linux-xilinx vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8074-1 linux-azure vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8074-2 linux-azure-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8031-3 linux-gcp, linux-gke vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8028-1 linux, linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8028-4 linux-aws-fips, linux-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8028-3 linux-realtime, linux-raspi-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8028-2 linux-realtime-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8028-7 linux-nvidia-lowlatency vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8031-2 linux-gcp-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8031-1 linux-gcp-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7934-1 linux-azure, linux-azure-6.14 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7936-1 linux-oem-6.14 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7921-2 linux-realtime-6.14 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7921-1 linux, linux-aws, linux-aws-6.14, linux-gcp, linux-hwe-6.14, linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- RHSA-2025:21463 Red Hat Security Advisory: kernel security update Red Hat Security Advisories (RHSA) · Jul 30, 2026
- SUSE-SU-2026:20560-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Jul 9, 2026
- openSUSE-SU-2025:20081-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:4140-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:21179-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:21139-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:21074-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:21056-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:4141-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:21040-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:21052-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:21064-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- WID-SEC-2026-0569 Google Android: Mehrere Schwachstellen BSI CERT-Bund (WID) · Mar 9, 2026
- NCSC-2026-0074 Kwetsbaarheden verholpen in Google Android en Samsung Mobile NCSC-NL (Netherlands) · Mar 3, 2026
- SUSE-SU-2025:4128-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2025:4132-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2025:4057-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2025:4301-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- ELSA-2025-21463 Moderate: kernel security update (Oracle Linux 10) Oracle Linux Security Advisories (ELSA) · Dec 4, 2025
- DLA-4379-1 linux-6.1 - security update Debian Security (DSA / DLA) · Nov 25, 2025
- DSA-6053-1 linux - security update Debian Security (DSA / DLA) · Nov 11, 2025
- ELSA-2025-25754 Important: Unbreakable Enterprise kernel security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Nov 9, 2025
- ALAS2023-2025-1254 Important: kernel6.12 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Oct 27, 2025
- ELSA-2025-20719 Important: Unbreakable Enterprise kernel security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Oct 24, 2025
- ALAS2023-2025-1223 Important: kernel security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Oct 14, 2025
References
- https://git.kernel.org/stable/c/b36462146d86b1f22e594fe4dae611dffacfb203
- https://git.kernel.org/stable/c/4cefe5be73886f383639fe0850bb72d5b568a7b9
- https://git.kernel.org/stable/c/208640e6225cc929a05adbf79d1df558add3e231
- https://git.kernel.org/stable/c/61ca2da5fb8f433ce8bbd1657c84a86272133e6b
- https://git.kernel.org/stable/c/0aeb54ac4cd5cf8f60131b4d9ec0b6dc9c27b20d