5.5

CVE-2026-31424: netfilter: x_tables: restrict xt_check_match/xt_check_target extensions for NFPROTO_ARP

Modified
AliasesUBUNTU-CVE-2026-31424DEBIAN-CVE-2026-31424
Published 13-04-2026Last modified 15-10-2026

Vulnerability summary

CVE-2026-31424 is a medium (CVSS 5.5) NULL Pointer Dereference vulnerability in linux. EPSS estimates a 0.12% chance of exploitation in the next 30 days, higher than 2% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 5.5, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
5.5/10
010
Medium · v3.1 (NVD)
EPSS score
0.12%
0%100%
Low · -0.05 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 31 · Related 29
MGASA-2026-0108MGASA-2026-0110SUSE-SU-2026:21834-1SUSE-SU-2026:2238-1USN-8567-1USN-8574-1

Timeline

  1. 13-04-2026
    PublishedVulnerability first disclosed.
  2. 15-10-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: x_tables: restrict xt_check_match/xt_check_target extensions for NFPROTO_ARP Weiming Shi says: xt_match and xt_target structs registered with NFPROTO_UNSPEC can be loaded by any protocol family through nft_compat. When such a match/target sets .hooks to restrict which hooks it may run on, the bitmask uses NF_INET_* constants. This is only correct for families whose hook layout matches NF_INET_*: IPv4, IPv6, INET, and bridge all share the same five hooks (PRE_ROUTING ... POST_ROUTING). ARP only has three hooks (IN=0, OUT=1, FORWARD=2) with different semantics. Because NF_ARP_OUT == 1 == NF_INET_LOCAL_IN, the .hooks validation silently passes for the wrong reasons, allowing matches to run on ARP chains where the hook assumptions (e.g. state->in being set on input hooks) do not hold. This leads to NULL pointer dereferences; xt_devgroup is one concrete example: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000044: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000220-0x0000000000000227] RIP: 0010:devgroup_mt+0xff/0x350 Call Trace: <TASK> nft_match_eval (net/netfilter/nft_compat.c:407) nft_do_chain (net/netfilter/nf_tables_core.c:285) nft_do_chain_arp (net/netfilter/nft_chain_filter.c:61) nf_hook_slow (net/netfilter/core.c:623) arp_xmit (net/ipv4/arp.c:666) </TASK> Kernel panic - not syncing: Fatal exception in interrupt Fix it by restricting arptables to NFPROTO_ARP extensions only. Note that arptables-legacy only supports: - arpt_CLASSIFY - arpt_mangle - arpt_MARK that provide explicit NFPROTO_ARP match/target declarations.

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.12%

Chance of exploitation in the next 30 days

Percentile

2%

Versus all other CVEs

30-day change

Decrease -0.05 pp

From 0.17% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu157 products
  • linuxAll versions (No fix recorded) | < 5.15.0-186.196 | < 6.8.0-136.136
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 5.15.0-1112.119 | < 6.8.0-1061.64
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ 9291747f118d6404e509747b85ff5f6dfec368d2, < 80e3c75f71c3ea1e62fcb032382de13e00a68f8b | ≥ 9291747f118d6404e509747b85ff5f6dfec368d2, < d9a0af9e43416aa50c0595e15fa01365a1c72c49 | ≥ 9291747f118d6404e509747b85ff5f6dfec368d2, < 1cd6313c8644bfebbd813a05da9daa21b09dd68c | ≥ 9291747f118d6404e509747b85ff5f6dfec368d2, < f00ac65c90ea475719e08d629e2e26c8b4e6999b | ≥ 9291747f118d6404e509747b85ff5f6dfec368d2, < e7e1b6bcb389c8708003d40613a59ff2496f6b1f | ≥ 9291747f118d6404e509747b85ff5f6dfec368d2, < dc3e27dd7d76e21106b8f9bbdc31f5da74a89014 | ≥ 9291747f118d6404e509747b85ff5f6dfec368d2, < 3e79374b03bf9a2f282f0eb1d0ac3776f7e0f28a | ≥ 9291747f118d6404e509747b85ff5f6dfec368d2, < 3d5d488f11776738deab9da336038add95d342d1 | 2.6.39
  • linux_kernel≥ 2.6.39, < 5.10.253 | ≥ 5.11, < 5.15.203 | ≥ 5.16, < 6.1.168 | ≥ 6.2, < 6.6.134 | ≥ 6.7, < 6.12.81 | ≥ 6.13, < 6.18.22 | ≥ 6.19, < 6.19.12 | 7.0:rc1 | 7.0:rc2 | 7.0:rc3 | 7.0:rc4 | 7.0:rc5 | 7.0:rc6
Debian1 product
  • linux< 6.1.170-1 | < 6.12.85-1 | < 6.19.12-1

3 vendors · 160 products

References

43 links
Show all 43 references