Answer in brief
CVE-2026-31424 records a Medium severity (CVSS 5.5) vulnerability in netfilter: x_tables: restrict xt_check_match/xt_check_target extensions for NFPROTO_ARP. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
Answer in brief
CVE-2026-31424 records a Medium severity (CVSS 5.5) vulnerability in netfilter: x_tables: restrict xt_check_match/xt_check_target extensions for NFPROTO_ARP. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 5.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=9291747f118d6404e509747b85ff5f6dfec368d2 <80e3c75f71c3ea1e62fcb032382de13e00a68f8b || >=9291747f118d6404e509747b85ff5f6dfec368d2 <d9a0af9e43416aa50c0595e15fa01365a1c72c49 || >=9291747f118d6404e509747b85ff5f6dfec368d2 <1cd6313c8644bfebbd813a05da9daa21b09dd68c || >=9291747f118d6404e509747b85ff5f6dfec368d2 <f00ac65c90ea475719e08d629e2e26c8b4e6999b || >=9291747f118d6404e509747b85ff5f6dfec368d2 <e7e1b6bcb389c8708003d40613a59ff2496f6b1f || >=9291747f118d6404e509747b85ff5f6dfec368d2 <dc3e27dd7d76e21106b8f9bbdc31f5da74a89014 || >=9291747f118d6404e509747b85ff5f6dfec368d2 <3e79374b03bf9a2f282f0eb1d0ac3776f7e0f28a || >=9291747f118d6404e509747b85ff5f6dfec368d2 <3d5d488f11776738deab9da336038add95d342d1 | 80e3c75f71c3ea1e62fcb032382de13e00a68f8b, d9a0af9e43416aa50c0595e15fa01365a1c72c49, 1cd6313c8644bfebbd813a05da9daa21b09dd68c, f00ac65c90ea475719e08d629e2e26c8b4e6999b, e7e1b6bcb389c8708003d40613a59ff2496f6b1f, dc3e27dd7d76e21106b8f9bbdc31f5da74a89014, 3e79374b03bf9a2f282f0eb1d0ac3776f7e0f28a, 3d5d488f11776738deab9da336038add95d342d1 |
| Linux/Linuxgeneric | 2.6.39 | Not reported |
| Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
| Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.5 <* | * |
| Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
| Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFPgeneric | >=V3.1.5 <* | * |
| Siemens/SIPLUS S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
| Siemens/SIPLUS S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.5 <* | * |
Published upstream
Apr 13, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Jul 14, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 14, 2026
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.
Quoted source text, attributed separately from HOL analysis.
CVSS is 5.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=9291747f118d6404e509747b85ff5f6dfec368d2 <80e3c75f71c3ea1e62fcb032382de13e00a68f8b || >=9291747f118d6404e509747b85ff5f6dfec368d2 <d9a0af9e43416aa50c0595e15fa01365a1c72c49 || >=9291747f118d6404e509747b85ff5f6dfec368d2 <1cd6313c8644bfebbd813a05da9daa21b09dd68c || >=9291747f118d6404e509747b85ff5f6dfec368d2 <f00ac65c90ea475719e08d629e2e26c8b4e6999b || >=9291747f118d6404e509747b85ff5f6dfec368d2 <e7e1b6bcb389c8708003d40613a59ff2496f6b1f || >=9291747f118d6404e509747b85ff5f6dfec368d2 <dc3e27dd7d76e21106b8f9bbdc31f5da74a89014 || >=9291747f118d6404e509747b85ff5f6dfec368d2 <3e79374b03bf9a2f282f0eb1d0ac3776f7e0f28a || >=9291747f118d6404e509747b85ff5f6dfec368d2 <3d5d488f11776738deab9da336038add95d342d1 | 80e3c75f71c3ea1e62fcb032382de13e00a68f8b, d9a0af9e43416aa50c0595e15fa01365a1c72c49, 1cd6313c8644bfebbd813a05da9daa21b09dd68c, f00ac65c90ea475719e08d629e2e26c8b4e6999b, e7e1b6bcb389c8708003d40613a59ff2496f6b1f, dc3e27dd7d76e21106b8f9bbdc31f5da74a89014, 3e79374b03bf9a2f282f0eb1d0ac3776f7e0f28a, 3d5d488f11776738deab9da336038add95d342d1 |
| Linux/Linuxgeneric | 2.6.39 | Not reported |
| Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
| Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.5 <* | * |
| Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
| Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFPgeneric | >=V3.1.5 <* | * |
| Siemens/SIPLUS S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
| Siemens/SIPLUS S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.5 <* | * |
Published upstream
Apr 13, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Jul 14, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 14, 2026
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.
Quoted source text, attributed separately from HOL analysis.