CVE-2026-63858Patch

LOWCVSS 7.8 · HIGH

Signal is active with 1 mentions in latest observed window

Immediate actions

  • Patch affected systems immediately

Recommended action window: Monitor and triage in normal cycle

NVD description

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_tables: add hook transactions for device deletions Restore the flag that indicates that the hook is going away, ie. NFT_HOOK_REMOVE, but add a new transaction object to track deletion of hooks without altering the basechain/flowtable hook_list during the preparation phase. The existing approach that moves the hook from the basechain/flowtable hook_list to transaction hook_list breaks netlink dump path readers of this RCU-protected list. It should be possible use an array for nft_trans_hook to store the deleted hooks to compact the representation but I am not expecting many hook object, specially now that wildcard support for devices is in place. Note that the nft_trans_chain_hooks() list contains a list of struct nft_trans_hook objects for DELCHAIN and DELFLOWTABLE commands, while this list stores struct nft_hook objects for NEWCHAIN and NEWFLOWTABLE. Note that new commands can be updated to use nft_trans_hook for consistency. This patch also adapts the event notification path to deal with the list of hook transactions.

0.5/ 10 priority

Sources & remediation

Weakness type (CWE)
CWE-362

Priority

LOW

Exploitation

NONE

PoC

NONE

Patch

AVAILABLE

Momentum

NONE

Threat summary

  • Patch or workaround signal is available
  • 1 mentions across 1 observed day

What's happening

  • Patch or workaround mentioned in 1 signal
  • Technical details provided in 1 signal
  • 1 total mentions across 1 day

Deep dive

Activity timeline1 mentions / 1d
00111Mentions · 2026-07-20: 1Patch / Workaround · 2026-07-20: 1Technical Details · 2026-07-20: 107-20
Signal classification1 categories
Patch
1100.0%
Referenced assets1 URL
Full discourse1 post
  • Windows Forum@windowsforum
    Patch

    🛡️ CVE-2026-63858 isn’t a Windows bug, but WSL 2, Hyper-V Linux VMs, Azure nodes and firewall appliances may still be exposed. Patch nftables before the sidecar becomes the incident. https://windowsforum.com/threads/cve-2026-63858-patch-linux-nftables-netdev-hook-deletion-bug.439570/?utm_source=x&utm_medium=social&utm_campaign=news_node84 #Cybersecurity #LinuxKernel #WindowsAdministration #Nftables https://t.co/r5ZLdjQQo8

    Post summary

    The tweet highlights an issue with NFTables in Linux affecting WSL2, Hyper‑V, Azure nodes, and firewall appliances, and urges users to apply a patch before exploiting the sidecar. No exploit code or active attacks are mentioned.

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    1.3K followersView on X

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