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CVE-2026-74660— netfilter: ebt_nflog: pin the NFLOG backend

Quick assessment

Affected
Linux Linux
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

在 Linux 内核中,已修复以下漏洞: netfilter: ebt_nflog:固定 NFLOG 后端模块引用 在每网络命名空间(per-net)清理之后运行,因此其最终的 RCU 宽限期也会等待那些从每网络绑定中获取日志记录器的读者完成。然而,与 和 前端不同, 在未持有所选日志记录器模块引用的情况下,向 传递了显式的 ULOG 日志类型。 因此,在卸载 模块后, 的 nflog 规则仍可能被调用。由此产生的竞态时序如下: 此时,全局 ULOG 日志记录器仍然已注册,因此 CPU 1 在 CPU 0 释放其内

CVSS 7.8 · High EPSS 0.13% · P2

Affected Version Matrix 18

VendorProduct Version RangeStatus
Linux Linux c83fa19603bdaeef17b815713dbbe3230c8a34ee< 3bcce49d617c593c7606083bfdb464a1761fa68d affected
c83fa19603bdaeef17b815713dbbe3230c8a34ee< 394d7939c6b2b9e6bea0844c89efb5913168d898 affected
c83fa19603bdaeef17b815713dbbe3230c8a34ee< 2cac4294f184c9bc19ff82552c62b80498694c39 affected
c83fa19603bdaeef17b815713dbbe3230c8a34ee< 9d8a94b48b393885e7f876c8ef68ed4da5012078 affected
c83fa19603bdaeef17b815713dbbe3230c8a34ee< 6809379a860b9fccbb5435bf08343f6d081ac68d affected
c83fa19603bdaeef17b815713dbbe3230c8a34ee< 47a119ec8a7e2d5c8c4e86fb1a56c4e696e500fb affected
c83fa19603bdaeef17b815713dbbe3230c8a34ee< e2ab7e878bdbe80104c879c31fd2d82a476703b8 affected
c83fa19603bdaeef17b815713dbbe3230c8a34ee< 30825970339c107bacaf7f61af90fcdb1f597ca1 affected
… +10 more rows
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I. Basic Information for CVE-2026-74660

Vulnerability Information

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Vulnerability Title
netfilter: ebt_nflog: pin the NFLOG backend
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: netfilter: ebt_nflog: pin the NFLOG backend nf_log_unregister() runs after the per-net teardown so its final RCU grace period also drains readers that obtained the logger from a per-net binding. However, ebt_nflog passes an explicit ULOG log type to nf_log_packet() without holding a reference on the selected logger module, unlike the xt_NFLOG and nft_log frontends. An ebtables nflog rule can therefore remain callable while nfnetlink_log is unloaded. The resulting interleaving is: CPU 0 CPU 1 nfnetlink_log_fini() unregister_pernet_subsys() kfree(nfnl_log_pernet(net)) ebt_nflog_tg() nf_log_packet() nfulnl_log_packet() instance_lookup_get_rcu() The global ULOG logger is still registered at this point, so CPU 1 dereferences the per-net state after CPU 0 has freed it. KASAN reported: BUG: KASAN: slab-use-after-free in instance_lookup_get_rcu Read of size 8 at addr ff110001052e6210 by task poc/92 Call Trace: instance_lookup_get_rcu+0x1ce/0x1f0 [nfnetlink_log] nfulnl_log_packet+0x248/0x2fb0 [nfnetlink_log] nf_log_packet+0x204/0x300 ebt_nflog_tg+0x351/0x550 ebt_do_table+0xedf/0x22b0 Allocated by task 90: __kmalloc_noprof+0x186/0x470 ops_init+0x6d/0x420 register_pernet_operations+0x2f6/0x670 register_pernet_subsys+0x23/0x40 Freed by task 93: kfree+0x131/0x3c0 ops_undo_list+0x3e3/0x700 unregister_pernet_operations+0x232/0x490 unregister_pernet_subsys+0x1c/0x30 nfnetlink_log_fini+0x34/0x450 [nfnetlink_log] Acquire the ULOG logger module reference when an ebt_nflog rule is validated and release it when the rule is destroyed. Request the NFLOG backend for legacy callers when needed, matching xt_NFLOG. This prevents module teardown until all ebt_nflog rules have stopped using the logger.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Source: CVE Program / CVE List V5
Vulnerability Type
N/A
Source: CVE Program / CVE List V5

Affected Products

Vendor Product Affected Versions CPE Subscribe
Linux Linux c83fa19603bdaeef17b815713dbbe3230c8a34ee ~ 3bcce49d617c593c7606083bfdb464a1761fa68d -
Linux Linux 4.12 -

II. Public POCs for CVE-2026-74660

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III. Intelligence Information for CVE-2026-74660

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Patches & Fixes for CVE-2026-74660 (7)

Same Patch Batch · Linux · 2026-08-22 · 150 CVEs total

CVE-2026-74612 10.0 CRITICAL veth: fix skb length accounting after XDP frag adjustment
CVE-2026-74705 10.0 CRITICAL udp: fix potential use-after-free in tunnel segmentation
CVE-2026-74730 9.8 CRITICAL NFS: Pin the 'struct nfs_server' during a FREE_STATEID call
CVE-2026-74591 9.8 CRITICAL mm/filemap: __filemap_add_folio() restore index before retrying
CVE-2026-74662 9.8 CRITICAL inet: frags: publish queues before arming timer
CVE-2026-74669 9.8 CRITICAL ipvs: clear IPv4 options after rebasing tunnel ICMP errors
CVE-2026-74608 9.8 CRITICAL smb: client: Fix use-after-free in cifs_try_adding_channels()
CVE-2026-74628 9.8 CRITICAL net/x25: fix use-after-free of the socket by its timers
CVE-2026-74688 9.8 CRITICAL sctp: clear control chunk transport if it is being removed
CVE-2026-74587 9.8 CRITICAL sctp: fix use-after-free of cached ASCONF chunk
CVE-2026-74588 9.8 CRITICAL sctp: keep chunk->transport in step with the list it is queued on
CVE-2026-74616 9.8 CRITICAL xdp: reject clones that overrun skb_shared_info tailroom
CVE-2026-74727 9.8 CRITICAL ovpn: skip rehash for peers already removed from by_id
CVE-2026-74586 9.8 CRITICAL sctp: clear new_transport when removing a peer
CVE-2026-74723 9.8 CRITICAL btrfs: lzo: reject inline extents without valid headers
CVE-2026-74617 9.8 CRITICAL dibs: initialise dibs->lock in dibs_dev_alloc()
CVE-2026-74611 9.8 CRITICAL tls: rx: restore msg_iter before TLS 1.3 optimistic retry
CVE-2026-74597 9.8 CRITICAL ip6_tunnel: clear skb2->cb[] in ip6ip6_err()
CVE-2026-74712 9.3 CRITICAL vdpa/mlx5: Fix buffer length in create_direct_keys()
CVE-2026-74665 9.1 CRITICAL net: fix skb length accounting after generic XDP frag adjustment

Showing top 20 of 150 CVEs. View all on vendor page &rarr; →

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