# CVE-2024-26863: hsr: Fix uninit-value access in hsr_get_node() > An attacker can trigger an uninitialized value access in the Linux kernel HSR module, potentially leaking sensitive memory contents. - **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`) - **Exploited in the wild:** Not known - **Login needed:** Any signed-in user - **Attackable:** Local or same network only - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 17 Apr 2024 - **Updated:** 15 Oct 2026 - **Also known as:** BELL-CVE-2024-26863, DEBIAN-CVE-2024-26863, GHSA-4xxr-7xxv-w3hj, UBUNTU-CVE-2024-26863 ## What is CVE-2024-26863? CVE-2024-26863 is a medium-severity vulnerability in Debian Debian Linux, published on 17 Apr 2024. It can only be exploited from the same machine or local network, with no action from the victim. ### Official description In the Linux kernel, the following vulnerability has been resolved: hsr: Fix uninit-value access in hsr_get_node() KMSAN reported the following uninit-value access issue [1]: ===================================================== BUG: KMSAN: uninit-value in hsr_get_node+0xa2e/0xa40 net/hsr/hsr_framereg.c:246 hsr_get_node+0xa2e/0xa40 net/hsr/hsr_framereg.c:246 fill_frame_info net/hsr/hsr_forward.c:577 [inline] hsr_forward_skb+0xe12/0x30e0 net/hsr/hsr_forward.c:615 hsr_dev_xmit+0x1a1/0x270 net/hsr/hsr_device.c:223 __netdev_start_xmit include/linux/netdevice.h:4940 [inline] netdev_start_xmit include/linux/netdevice.h:4954 [inline] xmit_one net/core/dev.c:3548 [inline] dev_hard_start_xmit+0x247/0xa10 net/core/dev.c:3564 __dev_queue_xmit+0x33b8/0x5130 net/core/dev.c:4349 dev_queue_xmit include/linux/netdevice.h:3134 [inline] packet_xmit+0x9c/0x6b0 net/packet/af_packet.c:276 packet_snd net/packet/af_packet.c:3087 [inline] packet_sendmsg+0x8b1d/0x9f30 net/packet/af_packet.c:3119 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] __sys_sendto+0x735/0xa10 net/socket.c:2191 __do_sys_sendto net/socket.c:2203 [inline] __se_sys_sendto net/socket.c:2199 [inline] __x64_sys_sendto+0x125/0x1c0 net/socket.c:2199 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x6d/0x140 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b Uninit was created at: slab_post_alloc_hook+0x129/0xa70 mm/slab.h:768 slab_alloc_node mm/slub.c:3478 [inline] kmem_cache_alloc_node+0x5e9/0xb10 mm/slub.c:3523 kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:560 __alloc_skb+0x318/0x740 net/core/skbuff.c:651 alloc_skb include/linux/skbuff.h:1286 [inline] alloc_skb_with_frags+0xc8/0xbd0 net/core/skbuff.c:6334 sock_alloc_send_pskb+0xa80/0xbf0 net/core/sock.c:2787 packet_alloc_skb net/packet/af_packet.c:2936 [inline] packet_snd net/packet/af_packet.c:3030 [inline] packet_sendmsg+0x70e8/0x9f30 net/packet/af_packet.c:3119 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] __sys_sendto+0x735/0xa10 net/socket.c:2191 __do_sys_sendto net/socket.c:2203 [inline] __se_sys_sendto net/socket.c:2199 [inline] __x64_sys_sendto+0x125/0x1c0 net/socket.c:2199 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x6d/0x140 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b CPU: 1 PID: 5033 Comm: syz-executor334 Not tainted 6.7.0-syzkaller-00562-g9f8413c4a66f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 ===================================================== If the packet type ID field in the Ethernet header is either ETH_P_PRP or ETH_P_HSR, but it is not followed by an HSR tag, hsr_get_skb_sequence_nr() reads an invalid value as a sequence number. This causes the above issue. This patch fixes the issue by returning NULL if the Ethernet header is not followed by an HSR tag. Weakness: CWE-908 (Use of Uninitialized Resource) ## Which versions are affected by CVE-2024-26863? It affects 2 products. Products: Debian Debian Linux, Linux kernel. ## How do I fix CVE-2024-26863? Apply the vendor's patch. ## Is CVE-2024-26863 being exploited? There is no known exploitation of CVE-2024-26863 in the wild and no public exploit code. ## Other vulnerabilities in Debian Debian Linux - [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild) - [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild) - [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild) - [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild) - [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2024-26863 and fix it if it is affected. What it is: CVE-2024-26863 is a medium-severity vulnerability in Debian Debian Linux, published on 17 Apr 2024. It can only be exploited from the same machine or local network, with no action from the victim. Exploitation: There is no known exploitation of CVE-2024-26863 in the wild and no public exploit code. Affected product: Debian Debian Linux. No package-level version data is available, so check the vendor advisory linked from the reference page. Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2024-26863/ (Markdown: https://insights.sbomify.com/CVE-2024-26863/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2024-26863 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-26863 - OSV: https://osv.dev/vulnerability/CVE-2024-26863 --- From sbomify Insights: https://insights.sbomify.com/CVE-2024-26863/ Summaries are generated and may contain mistakes; the official description above is the record.