CVE-2025-38500: Linux kernel · xfrm: interface: fix use-after-free after changing collect_md xfrm interface
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 6.8.0-1040.42~22.04.1 : patch Linux kernel soon.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 5% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 6.8.0-1040.42~22.04.1, 6.8.0-1040.46~22.04.1, 6.8.0-1041.43~22.04.1 +35
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 12 Aug 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- ubuntu.com/security/notices/USN-7791-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7792-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7791-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7798-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7799-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7792-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7800-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7801-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7791-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7801-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7792-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7808-1 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-aws-6.14pkg:deb/ubuntu/linux-aws-6.14?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azure-6.11pkg:deb/ubuntu/linux-azure-6.11?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
In the Linux kernel, the following vulnerability has been resolved: xfrm: interface: fix use-after-free after changing collect_md xfrm interface collect_md property on xfrm interfaces can only be set on device creation, thus xfrmi_changelink() should fail when called on such interfaces. The check to enforce this was done only in the case where the xi was returned from xfrmi_locate() which doesn't look for the collect_md interface, and thus the validation was never reached. Calling changelink would thus errornously place the special interface xi in the xfrmi_net->xfrmi hash, but since it also exists in the xfrmi_net->collect_md_xfrmi pointer it would lead to a double free when the net namespace was taken down [1]. Change the check to use the xi from netdev_priv which is available earlier in the function to prevent changes in xfrm collect_md interfaces. [1] resulting oops: [ 8.516540] kernel BUG at net/core/dev.c:12029! [ 8.516552] Oops: invalid opcode: 0000 [#1] SMP NOPTI [ 8.516559] CPU: 0 UID: 0 PID: 12 Comm: kworker/u80:0 Not tainted 6.15.0-virtme #5 PREEMPT(voluntary) [ 8.516565] Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 8.516569] Workqueue: netns cleanup_net [ 8.516579] RIP: 0010:unregister_netdevice_many_notify+0x101/0xab0 [ 8.516590] Code: 90 0f 0b 90 48 8b b0 78 01 00 00 48 8b 90 80 01 00 00 48 89 56 08 48 89 32 4c 89 80 78 01 00 00 48 89 b8 80 01 00 00 eb ac 90 <0f> 0b 48 8b 45 00 4c 8d a0 88 fe ff ff 48 39 c5 74 5c 41 80 bc 24 [ 8.516593] RSP: 0018:ffffa93b8006bd30 EFLAGS: 00010206 [ 8.516598] RAX: ffff98fe4226e000 RBX: ffffa93b8006bd58 RCX: ffffa93b8006bc60 [ 8.516601] RDX: 0000000000000004 RSI: 0000000000000000 RDI: dead000000000122 [ 8.516603] RBP: ffffa93b8006bdd8 R08: dead000000000100 R09: ffff98fe4133c100 [ 8.516605] R10: 0000000000000000 R11: 00000000000003d2 R12: ffffa93b8006be00 [ 8.516608] R13: ffffffff96c1a510 R14: ffffffff96c1a510 R15: ffffa93b8006be00 [ 8.516615] FS: 0000000000000000(0000) GS:ffff98fee73b7000(0000) knlGS:0000000000000000 [ 8.516619] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 8.516622] CR2: 00007fcd2abd0700 CR3: 000000003aa40000 CR4: 0000000000752ef0 [ 8.516625] PKRU: 55555554 [ 8.516627] Call Trace: [ 8.516632] <TASK> [ 8.516635] ? rtnl_is_locked+0x15/0x20 [ 8.516641] ? unregister_netdevice_queue+0x29/0xf0 [ 8.516650] ops_undo_list+0x1f2/0x220 [ 8.516659] cleanup_net+0x1ad/0x2e0 [ 8.516664] process_one_work+0x160/0x380 [ 8.516673] worker_thread+0x2aa/0x3c0 [ 8.516679] ? __pfx_worker_thread+0x10/0x10 [ 8.516686] kthread+0xfb/0x200 [ 8.516690] ? __pfx_kthread+0x10/0x10 [ 8.516693] ? __pfx_kthread+0x10/0x10 [ 8.516697] ret_from_fork+0x82/0xf0 [ 8.516705] ? __pfx_kthread+0x10/0x10 [ 8.516709] ret_from_fork_asm+0x1a/0x30 [ 8.516718] </TASK>
References
- ubuntu.com/security/CVE-2025-38500 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-38500 (opens in a new tab)
- git.kernel.org/linus/a90b2a1aaacbcf0f91d7e4868ad6c51c5dee814b (opens in a new tab)
- git.kernel.org/stable/c/5918c3f4800a3aef2173865e5903370f21e24f47 (opens in a new tab)
- git.kernel.org/stable/c/69a31f7a6a81f5ffd3812c442e09ff0be22960f1 (opens in a new tab)
- git.kernel.org/stable/c/a90b2a1aaacbcf0f91d7e4868ad6c51c5dee814b (opens in a new tab)
- git.kernel.org/stable/c/bfebdb85496e1da21d3cf05de099210915c3e706 (opens in a new tab)
- ubuntu.com/security/notices/USN-7791-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7792-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7791-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7798-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7799-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7792-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7800-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7801-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7791-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7801-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7792-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7808-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7809-1 (opens in a new tab)