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CVE-2026-93787— smb: client: bound dirent name against end of SMB response in cifs_filldir

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，以下漏洞已得到修复： smb: client: 在 中将目录项名称边界限制在 SMB 响应末尾 函数使用服务器提供的长度字段（ ），将条目名称从 SMB1 / 响应中拷贝出来。虽然通过 分配的 SMB 响应缓冲区具有明确的边界，但在最终调用 → → 读取 字节之前，系统并未检查 是否仍位于该缓冲区内部。 因此，一个恶意的 SMB1 服务器若在目录条目中返回过大的 ，将导致 在响应 slab 缓冲区末尾之外进行读取。任何能够通过 CIFS 挂载点列出目录（即在由攻击者控制的服务器提供的 CIF

CVSS 8.1 · High EPSS 0.33% · P24

Affected Version Matrix 8

VendorProduct Version RangeStatus
Linux Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2< 6e3b965267b7313903baba2739992b1e2e92d540 affected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2< 03003506c86f90312b0966283662c42fcab66e4b affected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2< f8cf09a53a0dc1da298e9dd0ba5f21710cf119d6 affected
2.6.12 affected
< 2.6.12 unaffected
6.12.111≤ 6.12.* unaffected
6.18.53≤ 6.18.* unaffected
7.2≤ * unaffected
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I. Basic Information for CVE-2026-93787

Vulnerability Information
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Vulnerability Title
smb: client: bound dirent name against end of SMB response in cifs_filldir
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: smb: client: bound dirent name against end of SMB response in cifs_filldir cifs_filldir() copies the entry name out of an SMB1 TRANS2_FIND_FIRST / FIND_NEXT response using a length (de.namelen) supplied by the server. The kmalloc'd SMB response buffer is bounded, but nothing checks that de.name + de.namelen still lies inside that buffer before the eventual filldir64() -> verify_dirent_name() -> memchr() reads namelen bytes. A hostile SMB1 server that returns an oversized FileNameLength in a directory entry therefore causes memchr() to read past the end of the response slab buffer. Reachable from any user who can list a directory on a CIFS mount served by an attacker-controlled server (getdents64() on the mounted directory): BUG: KASAN: slab-out-of-bounds in memchr+0x71/0x80 Read of size 1 at addr ffff88800e0640cc by task poc/115 Call Trace: dump_stack_lvl+0x64/0x80 print_report+0xce/0x620 kasan_report+0xec/0x120 memchr+0x71/0x80 filldir64+0x4c/0x6a0 cifs_filldir.constprop.0+0x9bb/0x1e00 cifs_readdir+0x2101/0x3380 iterate_dir+0x19c/0x520 __x64_sys_getdents64+0x126/0x210 do_syscall_64+0x107/0x5a0 entry_SYSCALL_64_after_hwframe+0x77/0x7f Pass the end-of-response pointer down to cifs_filldir() and reject entries whose name would extend past that boundary. This bug was discovered by Artiphishell's vTriage pipeline, which generated a userspace reproducer (an emulated hostile SMB1 server plus a getdents64() client) that reliably triggers the KASAN report on an unpatched kernel. The fix below was drafted with the Claude coding assistant; a userspace reproducer is available on request.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/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 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 ~ 6e3b965267b7313903baba2739992b1e2e92d540 -
Linux Linux 2.6.12 -

II. Public POCs for CVE-2026-93787

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III. Intelligence Information for CVE-2026-93787

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Patches & Fixes for CVE-2026-93787 (3)

Same Patch Batch · Linux · 2026-09-24 · 234 CVEs total

CVE-2026-93207 9.8 CRITICAL SUNRPC: Zero rpc_gss_wire_cred at svcauth_gss_decode_credbody() entry
CVE-2026-97413 9.8 CRITICAL RDMA/rtrs-srv: Fix integer underflow in process_read and process_write
CVE-2026-93228 9.1 CRITICAL svcrdma: Reject Write/Reply chunks with segcount 0
CVE-2026-93793 8.8 HIGH wifi: iwlwifi: mvm: validate TX_CMD response layout
CVE-2026-93799 8.8 HIGH wifi: iwlwifi: mvm: validate sta_id in BA window status notif
CVE-2026-93790 8.8 HIGH wifi: iwlwifi: mvm: fix out-of-bounds tid_data access in BA notif
CVE-2026-93806 8.8 HIGH wifi: cfg80211: validate assoc response length before status and IE access
CVE-2026-97442 8.8 HIGH wifi: ath11k: fix invalid data access in ath11k_dp_rx_h_undecap_nwifi
CVE-2026-97509 8.8 HIGH thunderbolt: Keep XDomain reference during the lifetime of a service
CVE-2026-97409 8.8 HIGH nvme-fc: Do not cancel requests in io target before it is initialized
CVE-2026-93280 8.8 HIGH greybus: audio: bound the topology section sizes against the fetched size
CVE-2026-93284 8.8 HIGH drm/pagemap: dma-unmap pages before handling migration errors
CVE-2026-97451 8.4 HIGH ACPICA: Fix integer overflow in acpi_ex_opcode_3A_1T_1R() (mid_op)
CVE-2026-97455 8.4 HIGH ACPICA: Fix use-after-free in acpi_ds_terminate_control_method()
CVE-2026-97452 8.4 HIGH ACPICA: Prevent adding invalid references
CVE-2026-97450 8.4 HIGH ACPICA: validate handler object type in two places
CVE-2026-93827 8.4 HIGH virtio-fs: avoid double-free on failed queue setup
CVE-2026-97433 8.2 HIGH nvme: validate FDP configuration descriptor sizes
CVE-2026-93221 8.1 HIGH nfsd: convert nfsd_net boolean flags to unsigned long flags word
CVE-2026-93282 8.1 HIGH ksmbd: fix maximum allowed access checks

Showing top 20 of 234 CVEs. View all on vendor page &rarr; →

IV. Related Vulnerabilities

Same product: Linux
Same vendor: Linux

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