🛡️ CVE-2023-53338 on Ubuntu — linux
Description
In the Linux kernel, the following vulnerability has been resolved: lwt: Fix return values of BPF xmit ops BPF encap ops can return different types of positive values, such like NET_RX_DROP, NET_XMIT_CN, NETDEV_TX_BUSY, and so on, from function skb_do_redirect and bpf_lwt_xmit_reroute. At the xmit hook, such return values would be treated implicitly as LWTUNNEL_XMIT_CONTINUE in ip(6)_finish_output2. When this happens, skbs that have been freed would continue to the neighbor subsystem, causing use-after-free bug and kernel crashes. To fix the incorrect behavior, skb_do_redirect return values can be simply discarded, the same as tc-egress behavior. On the other hand, bpf_lwt_xmit_reroute returns useful errors to local senders, e.g. PMTU information. Thus convert its return values to avoid the conflict with LWTUNNEL_XMIT_CONTINUE.
Distribution advisory
This page covers CVE-2023-53338 as tracked by Ubuntu, for the package linux. The fix is available in version 5.15.0-94.104; earlier versions remain affected.
How this vulnerability can be exploited
This issue can be reached over the network, attack complexity is low, an attacker needs no privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality high, integrity high, availability high.
CVSS metrics in full
The score comes from this vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Attack vector: Network — reachable from anywhere that can route to the service.
- Attack complexity: Low — the attack works reliably, with no preparation.
- Privileges required: None — an unauthenticated stranger can try it.
- User interaction: None — nobody has to be tricked into anything.
- Scope: Unchanged — the damage stays inside the vulnerable component.
- Confidentiality impact: High — total loss, or loss the attacker controls.
- Integrity impact: High — total loss, or loss the attacker controls.
- Availability impact: High — total loss, or loss the attacker controls.
Affected software
UBUNTU-CVE-2023-53338 is recorded against 122 packages.
- linux (fixed in 5.15.0-94.104)
- linux-allwinner-5.19
- linux-aws (fixed in 5.15.0-1053.58)
- linux-aws-5.0
- linux-aws-5.11
- linux-aws-5.13
- linux-aws-5.15 (fixed in 5.15.0-1053.58~20.04.1)
- linux-aws-5.19
- linux-aws-5.3
- linux-aws-5.4 (fixed in 5.4.0-1116.126~18.04.1)
- linux-aws-5.8
- linux-aws-6.2
- linux-aws-6.5
- linux-aws-fips (fixed in 5.15.0-1053.58+fips1)
- linux-aws-hwe
- linux-azure (fixed in 5.15.0-1056.64)
- linux-azure-4.15
- linux-azure-5.11
- linux-azure-5.13
- linux-azure-5.15 (fixed in 5.15.0-1056.64~20.04.1)
- linux-azure-5.19
- linux-azure-5.3
- linux-azure-5.4 (fixed in 5.4.0-1121.128~18.04.1)
- linux-azure-5.8
Show the remaining 98 packages
- linux-azure-6.11
- linux-azure-6.2
- linux-azure-6.5
- linux-azure-edge
- linux-azure-fde
- linux-azure-fde-5.19
- linux-azure-fde-6.2
- linux-azure-fips
- linux-bluefield
- linux-fips (fixed in 5.15.0-94.104+fips1)
- linux-gcp (fixed in 5.15.0-1051.59)
- linux-gcp-4.15
- linux-gcp-5.11
- linux-gcp-5.13
- linux-gcp-5.15 (fixed in 5.15.0-1051.59~20.04.1)
- linux-gcp-5.19
- linux-gcp-5.3
- linux-gcp-5.4 (fixed in 5.4.0-1120.129~18.04.1)
- linux-gcp-5.8
- linux-gcp-6.11
- linux-gcp-6.2
- linux-gcp-6.5
- linux-gcp-fips (fixed in 5.15.0-1055.63+fips2)
- linux-gke (fixed in 5.15.0-1050.55)
- linux-gke-4.15
- linux-gke-5.15
- linux-gke-5.4
- linux-gkeop (fixed in 5.15.0-1036.42)
- linux-gkeop-5.15
- linux-gkeop-5.4
- linux-hwe
- linux-hwe-5.11
- linux-hwe-5.13
- linux-hwe-5.15 (fixed in 5.15.0-94.104~20.04.1)
- linux-hwe-5.19
- linux-hwe-5.4 (fixed in 5.4.0-169.187~18.04.1)
- linux-hwe-5.8
- linux-hwe-6.11
- linux-hwe-6.2
- linux-hwe-6.5
- linux-hwe-edge
- linux-ibm (fixed in 5.15.0-1046.49)
- linux-ibm-5.15 (fixed in 5.15.0-1046.49~20.04.1)
- linux-ibm-5.4 (fixed in 5.4.0-1063.68~18.04.1)
- linux-intel
- linux-intel-5.13
- linux-intel-iot-realtime (fixed in 5.15.0-1046.48)
- linux-intel-iotg (fixed in 5.15.0-1047.53)
- linux-intel-iotg-5.15 (fixed in 5.15.0-1048.54~20.04.1)
- linux-iot (fixed in 5.4.0-1028.29)
- linux-kvm (fixed in 5.15.0-1050.55)
- linux-lowlatency (fixed in 5.15.0-94.104)
- linux-lowlatency-hwe-5.15 (fixed in 5.15.0-94.104~20.04.1)
- linux-lowlatency-hwe-5.19
- linux-lowlatency-hwe-6.11
- linux-lowlatency-hwe-6.2
- linux-lowlatency-hwe-6.5
- linux-nvidia (fixed in 5.15.0-1044.44)
- linux-nvidia-6.2
- linux-nvidia-6.5
- linux-nvidia-tegra (fixed in 5.15.0-1022.22)
- linux-nvidia-tegra-5.15 (fixed in 5.15.0-1022.22~20.04.1)
- linux-nvidia-tegra-igx (fixed in 5.15.0-1009.9)
- linux-oem
- linux-oem-5.10
- linux-oem-5.13
- linux-oem-5.14
- linux-oem-5.17
- linux-oem-5.6
- linux-oem-6.0
- linux-oem-6.1
- linux-oem-6.11
- linux-oem-6.5
- linux-oem-6.8
- linux-oracle (fixed in 5.15.0-1051.57)
- linux-oracle-5.0
- linux-oracle-5.11
- linux-oracle-5.13
- linux-oracle-5.15 (fixed in 5.15.0-1051.57~20.04.1)
- linux-oracle-5.3
- linux-oracle-5.4 (fixed in 5.4.0-1115.124~18.04.1)
- linux-oracle-5.8
- linux-oracle-6.5
- linux-raspi (fixed in 5.15.0-1046.49)
- linux-raspi-5.4 (fixed in 5.4.0-1100.112~18.04.1)
- linux-raspi-realtime
- linux-raspi2
- linux-realtime
- linux-riscv
- linux-riscv-5.11
- linux-riscv-5.15 (fixed in 5.15.0-1049.53~20.04.2)
- linux-riscv-5.19
- linux-riscv-5.8
- linux-riscv-6.5
- linux-starfive-5.19
- linux-starfive-6.2
- linux-starfive-6.5
- linux-xilinx-zynqmp (fixed in 5.15.0-1027.31)
Timeline and source
Published on 17 September 2025 and last revised on 19 August 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.
References
ubuntu.com (Report)
www.cve.org (Report)
git.kernel.org (Report)
git.kernel.org (Report)
git.kernel.org (Report)
git.kernel.org (Report)
git.kernel.org (Report)
git.kernel.org (Report)
git.kernel.org (Report)
git.kernel.org (Report)
Other advisories for this package
linux has other advisories on record. If you are patching this one, these are worth checking on the same host:
- DEBIAN-CVE-2022-4994 (published 30 Jul 2026)
- CVE-2026-35233 (4.4 Medium, published 1 May 2026)
- CVE-2026-21996 (3.3 Low, published 1 May 2026)
- CVE-2026-21991 (5.5 Medium, published 16 Mar 2026)
- CGA-mcwh-q4vm-9f29 (published 29 Jan 2026)
- CGA-w6xv-3fg4-grm5 (published 29 Jan 2026)
- CGA-4fpx-x3w2-4hfv (published 7 Jan 2026)
- CGA-fv2v-4h6c-q367 (published 7 Jan 2026)
CVE-2023-53338 on other distributions
Each distribution ships its own build and its own fixed version. Pick the one you run:
Details
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Affected Packages
| Software | From version | Fixed in |
|---|---|---|
| linux | — | 5.15.0-94.104 |
| linux-allwinner-5.19 | — | — |
| linux-aws | — | 5.15.0-1053.58 |
| linux-aws-5.0 | — | — |
| linux-aws-5.11 | — | — |
| linux-aws-5.13 | — | — |
| linux-aws-5.15 | — | 5.15.0-1053.58~20.04.1 |
| linux-aws-5.19 | — | — |
| linux-aws-5.3 | — | — |
| linux-aws-5.4 | — | 5.4.0-1116.126~18.04.1 |
| linux-aws-5.8 | — | — |
| linux-aws-6.2 | — | — |
| linux-aws-6.5 | — | — |
| linux-aws-fips | — | 5.15.0-1053.58+fips1 |
| linux-aws-hwe | — | — |
| linux-azure | — | 5.15.0-1056.64 |
| linux-azure-4.15 | — | — |
| linux-azure-5.11 | — | — |
| linux-azure-5.13 | — | — |
| linux-azure-5.15 | — | 5.15.0-1056.64~20.04.1 |
| linux-azure-5.19 | — | — |
| linux-azure-5.3 | — | — |
| linux-azure-5.4 | — | 5.4.0-1121.128~18.04.1 |
| linux-azure-5.8 | — | — |
| linux-azure-6.11 | — | — |
| linux-azure-6.2 | — | — |
| linux-azure-6.5 | — | — |
| linux-azure-edge | — | — |
| linux-azure-fde | — | — |
| linux-azure-fde-5.19 | — | — |
| linux-azure-fde-6.2 | — | — |
| linux-azure-fips | — | — |
| linux-bluefield | — | — |
| linux-fips | — | 5.15.0-94.104+fips1 |
| linux-gcp | — | 5.15.0-1051.59 |
| linux-gcp-4.15 | — | — |
| linux-gcp-5.11 | — | — |
| linux-gcp-5.13 | — | — |
| linux-gcp-5.15 | — | 5.15.0-1051.59~20.04.1 |
| linux-gcp-5.19 | — | — |
| linux-gcp-5.3 | — | — |
| linux-gcp-5.4 | — | 5.4.0-1120.129~18.04.1 |
| linux-gcp-5.8 | — | — |
| linux-gcp-6.11 | — | — |
| linux-gcp-6.2 | — | — |
| linux-gcp-6.5 | — | — |
| linux-gcp-fips | — | 5.15.0-1055.63+fips2 |
| linux-gke | — | 5.15.0-1050.55 |
| linux-gke-4.15 | — | — |
| linux-gke-5.15 | — | — |
| linux-gke-5.4 | — | — |
| linux-gkeop | — | 5.15.0-1036.42 |
| linux-gkeop-5.15 | — | — |
| linux-gkeop-5.4 | — | — |
| linux-hwe | — | — |
| linux-hwe-5.11 | — | — |
| linux-hwe-5.13 | — | — |
| linux-hwe-5.15 | — | 5.15.0-94.104~20.04.1 |
| linux-hwe-5.19 | — | — |
| linux-hwe-5.4 | — | 5.4.0-169.187~18.04.1 |
| linux-hwe-5.8 | — | — |
| linux-hwe-6.11 | — | — |
| linux-hwe-6.2 | — | — |
| linux-hwe-6.5 | — | — |
| linux-hwe-edge | — | — |
| linux-ibm | — | 5.15.0-1046.49 |
| linux-ibm-5.15 | — | 5.15.0-1046.49~20.04.1 |
| linux-ibm-5.4 | — | 5.4.0-1063.68~18.04.1 |
| linux-intel | — | — |
| linux-intel-5.13 | — | — |
| linux-intel-iot-realtime | — | 5.15.0-1046.48 |
| linux-intel-iotg | — | 5.15.0-1047.53 |
| linux-intel-iotg-5.15 | — | 5.15.0-1048.54~20.04.1 |
| linux-iot | — | 5.4.0-1028.29 |
| linux-kvm | — | 5.15.0-1050.55 |
| linux-lowlatency | — | 5.15.0-94.104 |
| linux-lowlatency-hwe-5.15 | — | 5.15.0-94.104~20.04.1 |
| linux-lowlatency-hwe-5.19 | — | — |
| linux-lowlatency-hwe-6.11 | — | — |
| linux-lowlatency-hwe-6.2 | — | — |
| linux-lowlatency-hwe-6.5 | — | — |
| linux-nvidia | — | 5.15.0-1044.44 |
| linux-nvidia-6.2 | — | — |
| linux-nvidia-6.5 | — | — |
| linux-nvidia-tegra | — | 5.15.0-1022.22 |
| linux-nvidia-tegra-5.15 | — | 5.15.0-1022.22~20.04.1 |
| linux-nvidia-tegra-igx | — | 5.15.0-1009.9 |
| linux-oem | — | — |
| linux-oem-5.10 | — | — |
| linux-oem-5.13 | — | — |
| linux-oem-5.14 | — | — |
| linux-oem-5.17 | — | — |
| linux-oem-5.6 | — | — |
| linux-oem-6.0 | — | — |
| linux-oem-6.1 | — | — |
| linux-oem-6.11 | — | — |
| linux-oem-6.5 | — | — |
| linux-oem-6.8 | — | — |
| linux-oracle | — | 5.15.0-1051.57 |
| linux-oracle-5.0 | — | — |
| linux-oracle-5.11 | — | — |
| linux-oracle-5.13 | — | — |
| linux-oracle-5.15 | — | 5.15.0-1051.57~20.04.1 |
| linux-oracle-5.3 | — | — |
| linux-oracle-5.4 | — | 5.4.0-1115.124~18.04.1 |
| linux-oracle-5.8 | — | — |
| linux-oracle-6.5 | — | — |
| linux-raspi | — | 5.15.0-1046.49 |
| linux-raspi-5.4 | — | 5.4.0-1100.112~18.04.1 |
| linux-raspi-realtime | — | — |
| linux-raspi2 | — | — |
| linux-realtime | — | — |
| linux-riscv | — | — |
| linux-riscv-5.11 | — | — |
| linux-riscv-5.15 | — | 5.15.0-1049.53~20.04.2 |
| linux-riscv-5.19 | — | — |
| linux-riscv-5.8 | — | — |
| linux-riscv-6.5 | — | — |
| linux-starfive-5.19 | — | — |
| linux-starfive-6.2 | — | — |
| linux-starfive-6.5 | — | — |
| linux-xilinx-zynqmp | — | 5.15.0-1027.31 |
References
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Exploit Protection
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