Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1359 CNY

100%
Buy Us a Coffee

CVE-2026-43249— 9p/xen: protect xen_9pfs_front_free against concurrent calls

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.

Linux kernel是美国Linux基金会的开源操作系统Linux所使用的内核。 Linux kernel存在安全漏洞，该漏洞源于xen_9pfs_front_free函数可能被并发调用，导致双重释放。

CVSS 8.8 · High EPSS 0.38% · P30

Possible ATT&CK Techniques 1 AI

T1211 · Exploitation for Stealth

Affected Version Matrix 24

VendorProduct Version RangeStatus
Linux Linux c15fe55d14b3b4ded5af2a3260877460a6ffb8ad< a5d00dff97118a32fcf5fec7a4c3f864c4620c4e affected
c15fe55d14b3b4ded5af2a3260877460a6ffb8ad< 59e7707492576bdbfa8c1dbe7d90791df31e4773 affected
c15fe55d14b3b4ded5af2a3260877460a6ffb8ad< bf841d43f7a33d75675ba7f4e214ac1c67913065 affected
c15fe55d14b3b4ded5af2a3260877460a6ffb8ad< ce8ded2e61f47747e31eeefb44dc24a2160a7e32 affected
be03c4fe72384366fd4077a70966bd3b8fc49013 affected
1ab4de11232e83b875b071aa44d1155634ca8a1e affected
7cc9dbae8a5f73bd555130384ea256018d28f283 affected
3e0359f151ac151abe3fa71040e450ed69cb824b affected
… +16 more rows
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2026-43249

Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title
9p/xen: protect xen_9pfs_front_free against concurrent calls
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: 9p/xen: protect xen_9pfs_front_free against concurrent calls The xenwatch thread can race with other back-end change notifications and call xen_9pfs_front_free() twice, hitting the observed general protection fault due to a double-free. Guard the teardown path so only one caller can release the front-end state at a time, preventing the crash. This is a fix for the following double-free: [ 27.052347] Oops: general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6b6b: 0000 [#1] SMP DEBUG_PAGEALLOC NOPTI [ 27.052357] CPU: 0 UID: 0 PID: 32 Comm: xenwatch Not tainted 6.18.0-02087-g51ab33fc0a8b-dirty #60 PREEMPT(none) [ 27.052363] RIP: e030:xen_9pfs_front_free+0x1d/0x150 [ 27.052368] Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 41 55 41 54 55 48 89 fd 48 c7 c7 48 d0 92 85 53 e8 cb cb 05 00 48 8b 45 08 48 8b 55 00 <48> 3b 28 0f 85 f9 28 35 fe 48 3b 6a 08 0f 85 ef 28 35 fe 48 89 42 [ 27.052377] RSP: e02b:ffffc9004016fdd0 EFLAGS: 00010246 [ 27.052381] RAX: 6b6b6b6b6b6b6b6b RBX: ffff88800d66e400 RCX: 0000000000000000 [ 27.052385] RDX: 6b6b6b6b6b6b6b6b RSI: 0000000000000000 RDI: 0000000000000000 [ 27.052389] RBP: ffff88800a887040 R08: 0000000000000000 R09: 0000000000000000 [ 27.052393] R10: 0000000000000000 R11: 0000000000000000 R12: ffff888009e46b68 [ 27.052397] R13: 0000000000000200 R14: 0000000000000000 R15: ffff88800a887040 [ 27.052404] FS: 0000000000000000(0000) GS:ffff88808ca57000(0000) knlGS:0000000000000000 [ 27.052408] CS: e030 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 27.052412] CR2: 00007f9714004360 CR3: 0000000004834000 CR4: 0000000000050660 [ 27.052418] Call Trace: [ 27.052420] <TASK> [ 27.052422] xen_9pfs_front_changed+0x5d5/0x720 [ 27.052426] ? xenbus_otherend_changed+0x72/0x140 [ 27.052430] ? __pfx_xenwatch_thread+0x10/0x10 [ 27.052434] xenwatch_thread+0x94/0x1c0 [ 27.052438] ? __pfx_autoremove_wake_function+0x10/0x10 [ 27.052442] kthread+0xf8/0x240 [ 27.052445] ? __pfx_kthread+0x10/0x10 [ 27.052449] ? __pfx_kthread+0x10/0x10 [ 27.052452] ret_from_fork+0x16b/0x1a0 [ 27.052456] ? __pfx_kthread+0x10/0x10 [ 27.052459] ret_from_fork_asm+0x1a/0x30 [ 27.052463] </TASK> [ 27.052465] Modules linked in: [ 27.052471] ---[ end trace 0000000000000000 ]---
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:A/AC:L/PR:N/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
Vulnerability Title
Linux kernel 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Linux kernel是美国Linux基金会的开源操作系统Linux所使用的内核。 Linux kernel存在安全漏洞，该漏洞源于xen_9pfs_front_free函数可能被并发调用，导致双重释放。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

Vendor Product Affected Versions CPE Subscribe
Linux Linux c15fe55d14b3b4ded5af2a3260877460a6ffb8ad ~ a5d00dff97118a32fcf5fec7a4c3f864c4620c4e -
Linux Linux 6.3 -

II. Public POCs for CVE-2026-43249

# POC Description Source Link Shenlong Link
AI-Generated POC Premium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-43249

请登录查看更多情报信息。

Patches & Fixes for CVE-2026-43249 (4)

Same Patch Batch · Linux · 2026-05-06 · 224 CVEs total

CVE-2026-43186 9.8 CRITICAL ipv6: ioam: fix heap buffer overflow in __ioam6_fill_trace_data()
CVE-2026-43185 9.8 CRITICAL ksmbd: fix signededness bug in smb_direct_prepare_negotiation()
CVE-2026-43125 9.8 CRITICAL dlm: validate length in dlm_search_rsb_tree
CVE-2026-43208 9.8 CRITICAL net: do not pass flow_id to set_rps_cpu()
CVE-2026-43198 9.8 CRITICAL tcp: fix potential race in tcp_v6_syn_recv_sock()
CVE-2026-43114 9.4 CRITICAL netfilter: nft_set_pipapo_avx2: don't return non-matching entry on expiry
CVE-2026-43117 9.1 CRITICAL btrfs: tracepoints: get correct superblock from dentry in event btrfs_sync_file()
CVE-2026-43083 9.1 CRITICAL net: ioam6: fix OOB and missing lock
CVE-2026-43197 9.1 CRITICAL netconsole: avoid OOB reads, msg is not nul-terminated
CVE-2026-43232 8.8 HIGH net: wan: farsync: Fix use-after-free bugs caused by unfinished tasklets
CVE-2026-43215 8.8 HIGH cifs: Fix locking usage for tcon fields
CVE-2026-43112 8.8 HIGH fs/smb/client: fix out-of-bounds read in cifs_sanitize_prepath
CVE-2026-43113 8.8 HIGH wifi: wl1251: validate packet IDs before indexing tx_frames
CVE-2026-43110 8.8 HIGH wifi: brcmfmac: validate bsscfg indices in IF events
CVE-2026-43187 8.8 HIGH xfs: delete attr leaf freemap entries when empty
CVE-2026-43283 8.8 HIGH net: ethernet: ec_bhf: Fix dma_free_coherent() dma handle
CVE-2026-43239 8.8 HIGH smb: client: prevent races in ->query_interfaces()
CVE-2026-43158 8.8 HIGH xfs: fix freemap adjustments when adding xattrs to leaf blocks
CVE-2026-43176 8.8 HIGH wifi: rtw89: pci: validate release report content before using for RTL8922DE
CVE-2026-43172 8.8 HIGH wifi: iwlwifi: fix 22000 series SMEM parsing

Showing top 20 of 224 CVEs. View all on vendor page &rarr; →

IV. Related Vulnerabilities

Same product: Linux
Same vendor: Linux

V. Comments for CVE-2026-43249

No comments yet

Leave a comment