7.8

CVE-2025-40206: linux

CVSS: 7.8v3.1HighDeferred
AliasesUBUNTU-CVE-2025-40206DEBIAN-CVE-2025-40206
Published 12-11-2025Last modified 15-10-2026
Open JSON

Vulnerability summary

CVE-2025-40206 is a high (CVSS 7.8) vulnerability in linux. EPSS estimates a 0.15% chance of exploitation in the next 30 days, higher than 4.1% of scored vulnerabilities.

Overall risk
31/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.8/10
010
High · v3.1 (CVE.org)
EPSS score
0.15%
0%100%
Low · +0.01 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 30 · Related 30
OPENSUSE-SU-2025:20172-1SUSE-SU-2025:4393-1SUSE-SU-2025:4422-1SUSE-SU-2025:4505-1SUSE-SU-2025:4516-1SUSE-SU-2025:4517-1

Timeline

  1. 12-11-2025
    PublishedVulnerability first disclosed.
  2. 15-10-2026
    Last modifiedVulnerability information updated.

Description

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 ^^^^^^^^^^^^^^^^^^^^^^^^

CVSS metrics

5 scores · 4 sources · 2 versions

EPSS trend

Probability

0.15%

Chance of exploitation in the next 30 days

Percentile

4%

Versus all other CVEs

30-day change

+0.01 pp

From 0.14% on 21-09-2026

21-09-202621-10-2026
EPSS score
0.15%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

No weakness data has been published for this record.

Affected systems

Ubuntu150 products
  • linuxAll versions (No fix recorded) | < 6.8.0-106.106 | < 6.17.0-14.14
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 6.8.0-1050.53 | < 6.17.0-1007.7
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Debian1 product
  • linux< 6.1.187-1 | < 6.12.57-1 | < 6.17.6-1
Linux1 product
  • linux≥ ee394f96ad7517fbc0de9106dcc7ce9efb14f264, < f31bcea12222a26d6f151df9c4a6d21f2eec1724 | ≥ ee394f96ad7517fbc0de9106dcc7ce9efb14f264, < 0028e0134c64d9ed21728341a74fcfc59cd0f944 | ≥ ee394f96ad7517fbc0de9106dcc7ce9efb14f264, < 7ea55a44493a5a36c3b3293b88bbe4841f9dbaf0 | ≥ ee394f96ad7517fbc0de9106dcc7ce9efb14f264, < 4c1cf72ec10be5a9ad264650cadffa1fbce6fabd | ≥ ee394f96ad7517fbc0de9106dcc7ce9efb14f264, < f359b809d54c6e3dd1d039b97e0b68390b0e53e4 | 5.4

3 vendors · 152 products

References

25 links
Show all 25 references