Linux Kernel up to 6.12.103/6.18.44/7.1.8 ipheth ipheth_sndbulk_callback use after free

CVSS Meta Temp Score
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7.8$0-$5k0.43-

Summaryinfo

A vulnerability identified as very critical has been detected in Linux Kernel up to 6.12.103/6.18.44/7.1.8. The impacted element is the function ipheth_sndbulk_callback of the component ipheth. The manipulation leads to use after free. This vulnerability is referenced as CVE-2026-74677. The attack can only be performed from a local environment. No exploit is available.

Detailsinfo

A vulnerability, which was classified as very critical, has been found in Linux Kernel up to 6.12.103/6.18.44/7.1.8. This issue affects the function ipheth_sndbulk_callback of the component ipheth. The manipulation with an unknown input leads to a use after free vulnerability. Using CWE to declare the problem leads to CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: net: usb: ipheth: fix carrier_work UAF on disconnect ipheth_sndbulk_callback() re-arms the carrier-check work on any non-zero URB status: else schedule_delayed_work(&dev->carrier_work, 0); Nothing ties that to the interface being up, so the work can be armed again after ipheth_close() has already drained it, and stay armed until the netdev whose private area embeds it is freed. On unplug with a TX URB in flight, ipheth_disconnect() drains the work through unregister_netdev() -> ipheth_close() -> cancel_delayed_work_sync() and only then calls ipheth_kill_urbs(). usb_kill_urb() completes the in-flight TX URB with -ENOENT, so ipheth_sndbulk_callback() runs after the drain and re-arms carrier_work. The same completion also re-arms the work if the interface is only brought down while a TX URB is in flight, and ipheth_carrier_check_work() then keeps re-queueing itself once a second. unregister_netdev() does not call ipheth_close() for an already-down interface, so nothing drains it on the later unplug either. In both cases free_netdev() frees the netdev while carrier_work is still pending, and ipheth_carrier_check_work() dereferences freed memory. Tie the work to the interface state instead of chasing the completion: disable it in ipheth_close() and enable it in ipheth_open(), so a schedule_delayed_work() from the URB completion is a no-op whenever the interface is not up. disable_delayed_work_sync() also waits for a running instance, so it fully replaces the cancel_delayed_work_sync() it takes the place of. The work starts out disabled in ipheth_probe() so the enable/disable counts balance from the first open. Reproduced under KASAN on linux-next (next-20260731) with dummy_hcd and raw-gadget standing in for the device, driving the second path above (the interface is already down, so unregister_netdev() does not call ipheth_close()): 15 of 15 unpatched boots report a slab-use-after-free in __run_timers(), freed by ipheth_disconnect() and re-armed from ipheth_sndbulk_callback() via queue_delayed_work_on(). The same trigger on a kernel differing only by this patch reports 0 of 15, and the carrier check still functions across open/close cycles. The reproducer needs an attached USB device that stops draining bulk OUT, plus a link down and unplug, driven as root. It is not a privilege boundary crossing and no exploit primitive was developed. Found by 0sec (https://0sec.ai).

The advisory is shared at git.kernel.org. The identification of this vulnerability is CVE-2026-74677 since 08/15/2026. The exploitation is known to be easy. An attack has to be approached locally. It demands that the victim is doing some kind of user interaction. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 08/22/2026).

Upgrading to version 6.12.104, 6.18.45 or 7.1.9 eliminates this vulnerability. Applying the patch d07133fe1befae9a1e4c4c5e46ef0b73d2992020/2c7496124e94c7f9c3daa5c5b1fb563ca9d62c45/48303f3ae0fa6e102f3fc7dbf1688cc179131962/fde39b8a521780391fb4e5bda2c0aa4928947f12 is able to eliminate this problem.

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Productinfo

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Version

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Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.2
VulDB Meta Temp Score: 7.8

VulDB Base Score: 8.2
VulDB Temp Score: 7.8
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.12.104/6.18.45/7.1.9
Patch: d07133fe1befae9a1e4c4c5e46ef0b73d2992020/2c7496124e94c7f9c3daa5c5b1fb563ca9d62c45/48303f3ae0fa6e102f3fc7dbf1688cc179131962/fde39b8a521780391fb4e5bda2c0aa4928947f12

Timelineinfo

08/15/2026 CVE reserved
08/22/2026 +7 days Advisory disclosed
08/22/2026 +0 days VulDB entry created
08/22/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-74677 (🔒)
GCVE (CVE): GCVE-0-2026-74677
GCVE (VulDB): GCVE-100-394445

Entryinfo

Created: 08/22/2026 18:44
Changes: 08/22/2026 18:44 (59)
Complete: 🔍
Cache ID: 216::103

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