Answer in brief
CVE-2025-40206 records a Unknown severity vulnerability in netfilter: nft_objref: validate objref and objrefmap expressions. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. 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). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=ee394f96ad7517fbc0de9106dcc7ce9efb14f264 <0028e0134c64d9ed21728341a74fcfc59cd0f944 || >=ee394f96ad7517fbc0de9106dcc7ce9efb14f264 <7ea55a44493a5a36c3b3293b88bbe4841f9dbaf0 || >=ee394f96ad7517fbc0de9106dcc7ce9efb14f264 <4c1cf72ec10be5a9ad264650cadffa1fbce6fabd || >=ee394f96ad7517fbc0de9106dcc7ce9efb14f264 <f359b809d54c6e3dd1d039b97e0b68390b0e53e4 | 0028e0134c64d9ed21728341a74fcfc59cd0f944, 7ea55a44493a5a36c3b3293b88bbe4841f9dbaf0, 4c1cf72ec10be5a9ad264650cadffa1fbce6fabd, f359b809d54c6e3dd1d039b97e0b68390b0e53e4 |
| Linux/Linuxgeneric | 5.4 | Not reported |
Published upstream
Nov 12, 2025
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_objref: validate objref and objrefmap expressions Referencing a synproxy stateful object from OUTPUT hook causes kernel crash due to infinite recursive calls: BUG: TASK stack guard page was hit at 000000008bda5b8c (stack is 000000003ab1c4a5..00000000494d8b12) [...] Call Trace: __find_rr_leaf+0x99/0x230 fib6_table_lookup+0x13b/0x2d0 ip6_pol_route+0xa4/0x400 fib6_rule_lookup+0x156/0x240 ip6_route_output_flags+0xc6/0x150 __nf_ip6_route+0x23/0x50 synproxy_send_tcp_ipv6+0x106/0x200 synproxy_send_client_synack_ipv6+0x1aa/0x1f0 nft_synproxy_do_eval+0x263/0x310 nft_do_chain+0x5a8/0x5f0 [nf_tables nft_do_chain_inet+0x98/0x110 nf_hook_slow+0x43/0xc0 __ip6_local_out+0xf0/0x170 ip6_local_out+0x17/0x70 synproxy_send_tcp_ipv6+0x1a2/0x200 synproxy_send_client_synack_ipv6+0x1aa/0x1f0 [...] Implement objref and objrefmap expression validate functions. Currently, only NFT_OBJECT_SYNPROXY object type requires validation. This will also handle a jump to a chain using a synproxy object from the OUTPUT hook. Now when trying to reference a synproxy object in the OUTPUT hook, nft will produce the following error: synproxy_crash.nft: Error: Could not process rule: Operation not supported synproxy name mysynproxy ^^^^^^^^^^^^^^^^^^^^^^^^
Quoted source text, attributed separately from HOL analysis.
Answer in brief
CVE-2025-40206 records a Unknown severity vulnerability in netfilter: nft_objref: validate objref and objrefmap expressions. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. 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). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=ee394f96ad7517fbc0de9106dcc7ce9efb14f264 <0028e0134c64d9ed21728341a74fcfc59cd0f944 || >=ee394f96ad7517fbc0de9106dcc7ce9efb14f264 <7ea55a44493a5a36c3b3293b88bbe4841f9dbaf0 || >=ee394f96ad7517fbc0de9106dcc7ce9efb14f264 <4c1cf72ec10be5a9ad264650cadffa1fbce6fabd || >=ee394f96ad7517fbc0de9106dcc7ce9efb14f264 <f359b809d54c6e3dd1d039b97e0b68390b0e53e4 | 0028e0134c64d9ed21728341a74fcfc59cd0f944, 7ea55a44493a5a36c3b3293b88bbe4841f9dbaf0, 4c1cf72ec10be5a9ad264650cadffa1fbce6fabd, f359b809d54c6e3dd1d039b97e0b68390b0e53e4 |
| Linux/Linuxgeneric | 5.4 | Not reported |
Published upstream
Nov 12, 2025
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_objref: validate objref and objrefmap expressions Referencing a synproxy stateful object from OUTPUT hook causes kernel crash due to infinite recursive calls: BUG: TASK stack guard page was hit at 000000008bda5b8c (stack is 000000003ab1c4a5..00000000494d8b12) [...] Call Trace: __find_rr_leaf+0x99/0x230 fib6_table_lookup+0x13b/0x2d0 ip6_pol_route+0xa4/0x400 fib6_rule_lookup+0x156/0x240 ip6_route_output_flags+0xc6/0x150 __nf_ip6_route+0x23/0x50 synproxy_send_tcp_ipv6+0x106/0x200 synproxy_send_client_synack_ipv6+0x1aa/0x1f0 nft_synproxy_do_eval+0x263/0x310 nft_do_chain+0x5a8/0x5f0 [nf_tables nft_do_chain_inet+0x98/0x110 nf_hook_slow+0x43/0xc0 __ip6_local_out+0xf0/0x170 ip6_local_out+0x17/0x70 synproxy_send_tcp_ipv6+0x1a2/0x200 synproxy_send_client_synack_ipv6+0x1aa/0x1f0 [...] Implement objref and objrefmap expression validate functions. Currently, only NFT_OBJECT_SYNPROXY object type requires validation. This will also handle a jump to a chain using a synproxy object from the OUTPUT hook. Now when trying to reference a synproxy object in the OUTPUT hook, nft will produce the following error: synproxy_crash.nft: Error: Could not process rule: Operation not supported synproxy name mysynproxy ^^^^^^^^^^^^^^^^^^^^^^^^
Quoted source text, attributed separately from HOL analysis.