CVE-2026-45844netfilter: arp_tables: fix IEEE1394 ARP payload parsing
- 5.5MediumCVSS base score
- 0.13%Exploitation in 30 daysEPSS · top 97% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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 <[email protected]>.
Timeline
ID reserved
By Linux
- 14 days later
· 14 days later
Published
- 5 months later
· 5 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Modified | 3.1 | Medium5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.13% · top 97% of all CVEs (12 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.5.
Affected products
- affected 6752c8db8e0cfedb44ba62806dd15b383ed64000 – < 0f23a1457695f1a61f64367e39f0f9cfa29947d1
- affected 6752c8db8e0cfedb44ba62806dd15b383ed64000 – < 1e285362ef7096eb12733370d59e033f4a1d294a
- affected 6752c8db8e0cfedb44ba62806dd15b383ed64000 – < 84e8536c981338d0d8cc6e712cf71a936a93e13f
- affected 6752c8db8e0cfedb44ba62806dd15b383ed64000 – < ad9973df8e0eeb123d9ec4d18828e05b7d44ff4b
- affected 6752c8db8e0cfedb44ba62806dd15b383ed64000 – < 03ea11dbefaa55c502735ee551c89ef773fe753b
- affected 6752c8db8e0cfedb44ba62806dd15b383ed64000 – < 1c55053f8ffdc060006df898fd3664e3d1bfac7b
- affected 6752c8db8e0cfedb44ba62806dd15b383ed64000 – < ac698d81fd6619c7504cee913f1cab5285fba1b7
- affected 6752c8db8e0cfedb44ba62806dd15b383ed64000 – < 1e8e3f449b1e73b73a843257635b9c50f0cc0f0a
- affected 3.10
- unaffected < 3.10
- unaffected 5.10.258 – ≤ 5.10.*
- unaffected 5.15.209 – ≤ 5.15.*
- unaffected 6.1.175 – ≤ 6.1.*
- unaffected 6.6.141 – ≤ 6.6.*
- unaffected 6.12.91 – ≤ 6.12.*
- unaffected 6.18.33 – ≤ 6.18.*
- unaffected 7.0.10 – ≤ 7.0.*
- unaffected 7.1 – ≤ *
References
References9
- https://git.kernel.org/stable/c/0f23a1457695f1a61f64367e39f0f9cfa29947d1 (opens in a new tab)
- https://git.kernel.org/stable/c/1e285362ef7096eb12733370d59e033f4a1d294a (opens in a new tab)
- https://git.kernel.org/stable/c/84e8536c981338d0d8cc6e712cf71a936a93e13f (opens in a new tab)
- https://git.kernel.org/stable/c/ad9973df8e0eeb123d9ec4d18828e05b7d44ff4b (opens in a new tab)
- https://git.kernel.org/stable/c/03ea11dbefaa55c502735ee551c89ef773fe753b (opens in a new tab)
- https://git.kernel.org/stable/c/1c55053f8ffdc060006df898fd3664e3d1bfac7b (opens in a new tab)
- https://git.kernel.org/stable/c/ac698d81fd6619c7504cee913f1cab5285fba1b7 (opens in a new tab)
- https://git.kernel.org/stable/c/1e8e3f449b1e73b73a843257635b9c50f0cc0f0a (opens in a new tab)
- https://cert-portal.siemens.com/productcert/html/ssa-784472.html (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-32170 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-45844)Record last updated .