# CVE-2026-45844: netfilter: arp_tables: fix IEEE1394 ARP payload parsing > Incorrect ARP payload parsing on IEEE1394 interfaces causes arptables to drop valid packets or corrupt data, requiring specific hardware configuration to exploit. - **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:** 27 May 2026 - **Updated:** 15 Oct 2026 - **Also known as:** AZL-88577, BELL-CVE-2026-45844, DEBIAN-CVE-2026-45844, GHSA-v3rr-h24h-xgqw, ROOT-OS-DEBIAN-11-CVE-2026-45844, ROOT-OS-DEBIAN-12-CVE-2026-45844, ROOT-OS-DEBIAN-13-CVE-2026-45844, ROOT-OS-UBUNTU-2204-CVE-2026-45844, ROOT-OS-UBUNTU-2404-CVE-2026-45844, UBUNTU-CVE-2026-45844 ## What is CVE-2026-45844? CVE-2026-45844 is a medium-severity vulnerability in Linux kernel, published on 27 May 2026. 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: netfilter: arp_tables: fix IEEE1394 ARP payload parsing Weiming Shi says: "arp_packet_match() unconditionally parses the ARP payload assuming two hardware addresses are present (source and target). However, IPv4-over-IEEE1394 ARP (RFC 2734) omits the target hardware address field, and arp_hdr_len() already accounts for this by returning a shorter length for ARPHRD_IEEE1394 devices. As a result, on IEEE1394 interfaces arp_packet_match() advances past a nonexistent target hardware address and reads the wrong bytes for both the target device address comparison and the target IP address. This causes arptables rules to match against garbage data, leading to incorrect filtering decisions: packets that should be accepted may be dropped and vice versa. The ARP stack in net/ipv4/arp.c (arp_create and arp_process) already handles this correctly by skipping the target hardware address for ARPHRD_IEEE1394. Apply the same pattern to arp_packet_match()." Mangle the original patch to always return 0 (no match) in case user matches on the target hardware address which is never present in IEEE1394. Note that this returns 0 (no match) for either normal and inverse match because matching in the target hardware address in ARPHRD_IEEE1394 has never been supported by arptables. This is intentional, matching on the target hardware address should never evaluate true for ARPHRD_IEEE1394. Moreover, adjust arpt_mangle to drop the packet too as AI suggests: In arpt_mangle, the logic assumes a standard ARP layout. Because IEEE1394 (FireWire) omits the target hardware address, the linear pointer arithmetic miscalculates the offset for the target IP address. This causes mangling operations to write to the wrong location, leading to packet corruption. To ensure safety, this patch drops packets (NF_DROP) when mangling is requested for these fields on IEEE1394 devices, as the current implementation cannot correctly map the FireWire ARP payload. This omits both mangling target hardware and IP address. Even if IP address mangling should be possible in IEEE1394, this would require to adjust arpt_mangle offset calculation, which has never been supported. Based on patch from Weiming Shi . ## Which versions are affected by CVE-2026-45844? It affects 1 product. Products: Linux kernel. ## How do I fix CVE-2026-45844? Apply the vendor's patch. ## Is CVE-2026-45844 being exploited? There is no known exploitation of CVE-2026-45844 in the wild and no public exploit code. ## Other vulnerabilities in Linux kernel - [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild) - [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild) - [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild) - [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild) - [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2026-45844 and fix it if it is affected. What it is: CVE-2026-45844 is a medium-severity vulnerability in Linux kernel, published on 27 May 2026. 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-2026-45844 in the wild and no public exploit code. Affected product: Linux kernel. 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-2026-45844/ (Markdown: https://insights.sbomify.com/CVE-2026-45844/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2026-45844 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-45844 - OSV: https://osv.dev/vulnerability/CVE-2026-45844 --- From sbomify Insights: https://insights.sbomify.com/CVE-2026-45844/ Summaries are generated and may contain mistakes; the official description above is the record.