CVE-2024-26863 — hsr: Fix uninit-value access in hsr_get_node()
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.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.2% (30-day exploitation probability)+2
- Technical severity (medium)+3
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Debian Debian Linux, Linux Linux, Linux Linux Kernel).
- Apply the fixed version or the patch documented under Remediation.
- Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Debian | Debian Linux | version 10.0 | Vulnerable | NIST National Vulnerability Database |
| Linux | Linux |
≥ f266a683a4804dc499efc6c2206ef68efed029d0 and < e3b2bfb8ff1810a537b2aa55ba906a6743ed120cversion 3.17≥ f266a683a4804dc499efc6c2206ef68efed029d0 and < ddbec99f58571301679addbc022256970ca3eac6≥ f266a683a4804dc499efc6c2206ef68efed029d0 and < 09e5cdbe2cc88c3c758927644a3eb02fac317209≥ f266a683a4804dc499efc6c2206ef68efed029d0 and < 97d2148ea435dff4b4e71817c9032eb321bcd37e≥ f266a683a4804dc499efc6c2206ef68efed029d0 and < 39cc316fb3bc5e7c9dc5eed314fe510d119c6862≥ f266a683a4804dc499efc6c2206ef68efed029d0 and < 1ed222ca7396938eb1ab2d034f1ba0d8b00a7122≥ f266a683a4804dc499efc6c2206ef68efed029d0 and < a809bbfd0e503351d3051317288a70a4569a4949 and 2 more≥ f266a683a4804dc499efc6c2206ef68efed029d0 and < 7fb2d4d6bb1c85f7a23aace0ed6c86a95dea792a≥ f266a683a4804dc499efc6c2206ef68efed029d0 and < 889ed056eae7fda85b769a9ab33c093379c45428 |
Vulnerable | CVE Program (cve.org) e CISA ADP |
| Linux | Linux Kernel | ≥ 6.8 and < 6.8.2≥ 6.7 and < 6.7.11≥ 6.2 and < 6.6.23≥ 5.16 and < 6.1.83≥ 5.11 and < 5.15.153≥ 5.5 and < 5.10.214≥ 4.20 and < 5.4.273≥ 3.17 and < 4.19.311 | Vulnerable | NIST National Vulnerability Database |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 5.5 | CVSS 3.1 | Medium | 1.8 | 3.6 | nvd@nist.gov via NIST National Vulnerability Database |
| 5.5 | CVSS 3.1 | Medium | — | — | GitHub, Inc. via GitHub Security Advisories |
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H (score shown at the top: nvd@nist.gov) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
EPSS over time FIRST
Oct 14, 2026 → Oct 15, 2026 · 2 reading(s) · max 0.25%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
- Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · linux/linux
- SSVC assessment updated
- Record published
- Fix documented
- Affected products added · linux/linux kernel, debian/debian linux
- CVSS changed · 5.5
- Source status changed · → Modified
- Record created in this database
- 2024
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 2× References added · Oct 14, 2026 – Oct 14, 2026
- 1× Official description updated · Oct 14, 2026 – Oct 14, 2026
References
15 on the record
- git.kernel.org/stable/c/09e5cdbe2cc88c3c758927644a3eb02fac317209
- git.kernel.org/stable/c/97d2148ea435dff4b4e71817c9032eb321bcd37e
- git.kernel.org/stable/c/889ed056eae7fda85b769a9ab33c093379c45428
- git.kernel.org/stable/c/7fb2d4d6bb1c85f7a23aace0ed6c86a95dea792a
- git.kernel.org/stable/c/1ed222ca7396938eb1ab2d034f1ba0d8b00a7122
- git.kernel.org/stable/c/39cc316fb3bc5e7c9dc5eed314fe510d119c6862
- git.kernel.org/stable/c/a809bbfd0e503351d3051317288a70a4569a4949
- git.kernel.org/stable/c/ddbec99f58571301679addbc022256970ca3eac6
- git.kernel.org/stable/c/e3b2bfb8ff1810a537b2aa55ba906a6743ed120c
- lists.debian.org/debian-lts-announce/2024/06/msg00017.html
- nvd.nist.gov/vuln/detail/CVE-2024-26863
- cert-portal.siemens.com/productcert/html/ssa-398330.html
- github.com/advisories/GHSA-4xxr-7xxv-w3hj
- lists.debian.org/debian-lts-announce/2024/06/msg00020.html
- cert-portal.siemens.com/productcert/html/ssa-265688.html
Elsewhere on this site
Related CVEs (same products)
- Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 22h
- Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 22h
- Unknown CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 1d
- Unknown CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 1d
- Unknown CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 1d
- Unknown CVE-2026-98427 net/sched: codel: bound the dropping loop per dequeue call 1d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2024-26863 is "hsr: Fix uninit-value access in hsr_get_node()", rated Medium. It affects Debian Linux (Debian); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 5.5 describes technical severity. EPSS 0.25% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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