Linux Kernel up to 7.1.8 VXLAN vxlan_changelink use after free

| CVSS Meta Temp Score | Current Exploit Price (≈) | CTI Interest Score |
|---|---|---|
| 9.5 | $5k-$25k | 1.29- |
Summary
A vulnerability was found in Linux Kernel up to 7.1.8 and classified as very critical. Affected by this issue is the function vxlan_changelink of the component VXLAN. Executing a manipulation can lead to use after free.
The identification of this vulnerability is CVE-2026-74615. The attack may be launched remotely. There is no exploit available.
Details
A vulnerability has been found in Linux Kernel up to 7.1.8 and classified as very critical. This vulnerability affects the function vxlan_changelink of the component VXLAN. The manipulation with an unknown input leads to a use after free vulnerability. The CWE definition for the vulnerability is CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:
In the Linux kernel, the following vulnerability has been resolved: vxlan: do not arm the ageing timer on a device that is down vxlan_changelink() arms vxlan->age_timer whenever the requested ageing interval differs from the configured one: if (conf.age_interval != vxlan->cfg.age_interval) mod_timer(&vxlan->age_timer, jiffies); There is no netif_running() test, so the timer is armed even on a device that was never brought up. The only synchronous cancel in the driver is the timer_delete_sync() in vxlan_stop(), which is .ndo_stop. netif_close_many() drops devices without IFF_UP before __dev_close_many() runs, so that cancel is skipped for such a device. vxlan_setup() sets dev->needs_free_netdev = true and age_timer is a member of struct vxlan_dev, so free_netdev() releases the allocation the timer lives in while it is still queued on a timer_base. expire_timers() unlinks the entry before it loads timer->function, so the timer core writes through the freed object's list pointers: BUG: KASAN: slab-use-after-free in __run_timers+0x208/0x654 Write of size 8 at addr ffff00001adace68 by task true/192 __asan_store8+0x84/0xac __run_timers+0x208/0x654 run_timer_softirq+0x154/0x18c Allocated by task 189: alloc_netdev_mqs+0x64/0x720 rtnl_create_link+0x4ac/0x520 rtnl_newlink+0x758/0xd00 Freed by task 191: netdev_release+0x40/0x58 netdev_run_todo+0x4a4/0x8c0 rtnl_dellink+0x200/0x4e8 The rtnl operations involved are netns-scoped, so an unprivileged user can perform them in a new user and network namespace. Arming the timer on a down device never had an effect: vxlan_cleanup() returns early on !netif_running(), and vxlan_open() arms the timer for any non-zero interval once the device is brought up. Add the missing test. Discovered by XBOW, triaged by Baul Lee <[email protected]>
The advisory is shared for download at git.kernel.org. This vulnerability was named CVE-2026-74615 since 08/15/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 08/22/2026).
Upgrading to version 5.10.265, 5.15.216, 6.1.183, 6.6.152, 6.12.104, 6.18.45 or 7.1.9 eliminates this vulnerability. Applying the patch be44d79d14d7f9ae7c8ffb7272142005341b5123/26c179d47403d2f919ee914cc02c31d896b59fee/9dc561f0522c35bdd66e0646a748814a138ec4ca/619dd29045e439d0b0f8c6d4fec1af447a050680/6b095e99b9e67ea31f0c4b00260e010898253519/46bb297ad77680e009244f067f27d51cf5b8c7cf/6b4119af544996a545cf84b16f1dbce829ba0de8/b37971686ec59fb027fa4910ba16805e68fddb97 is able to eliminate this problem.
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Product
Type
Vendor
Name
Version
- 5.10.264
- 5.15.215
- 6.1.182
- 6.6.151
- 6.12.103
- 6.18.0
- 6.18.1
- 6.18.2
- 6.18.3
- 6.18.4
- 6.18.5
- 6.18.6
- 6.18.7
- 6.18.8
- 6.18.9
- 6.18.10
- 6.18.11
- 6.18.12
- 6.18.13
- 6.18.14
- 6.18.15
- 6.18.16
- 6.18.17
- 6.18.18
- 6.18.19
- 6.18.20
- 6.18.21
- 6.18.22
- 6.18.23
- 6.18.24
- 6.18.25
- 6.18.26
- 6.18.27
- 6.18.28
- 6.18.29
- 6.18.30
- 6.18.31
- 6.18.32
- 6.18.33
- 6.18.34
- 6.18.35
- 6.18.36
- 6.18.37
- 6.18.38
- 6.18.39
- 6.18.40
- 6.18.41
- 6.18.42
- 6.18.43
- 6.18.44
- 7.1.0
- 7.1.1
- 7.1.2
- 7.1.3
- 7.1.4
- 7.1.5
- 7.1.6
- 7.1.7
- 7.1.8
License
Website
- Vendor: https://www.kernel.org/
CPE 2.3
CPE 2.2
CVSSv4
VulDB Vector: 🔒VulDB Reliability: 🔍
CVSSv3
VulDB Meta Base Score: 10.0VulDB Meta Temp Score: 9.5
VulDB Base Score: 10.0
VulDB Temp Score: 9.5
VulDB Vector: 🔒
VulDB Reliability: 🔍
CVSSv2
| AV | AC | Au | C | I | A |
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| 💳 | 💳 | 💳 | 💳 | 💳 | 💳 |
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| Vector | Complexity | Authentication | Confidentiality | Integrity | Availability |
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| Unlock | Unlock | Unlock | Unlock | Unlock | Unlock |
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍
Exploiting
Class: Use after freeCWE: CWE-416 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒
Physical: No
Local: No
Remote: Yes
Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒
| 0-Day | Unlock | Unlock | Unlock | Unlock |
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| Today | Unlock | Unlock | Unlock | Unlock |
Threat Intelligence
Interest: 🔍Active Actors: 🔍
Active APT Groups: 🔍
Countermeasures
Recommended: UpgradeStatus: 🔍
0-Day Time: 🔒
Upgrade: Kernel 5.10.265/5.15.216/6.1.183/6.6.152/6.12.104/6.18.45/7.1.9
Patch: be44d79d14d7f9ae7c8ffb7272142005341b5123/26c179d47403d2f919ee914cc02c31d896b59fee/9dc561f0522c35bdd66e0646a748814a138ec4ca/619dd29045e439d0b0f8c6d4fec1af447a050680/6b095e99b9e67ea31f0c4b00260e010898253519/46bb297ad77680e009244f067f27d51cf5b8c7cf/6b4119af544996a545cf84b16f1dbce829ba0de8/b37971686ec59fb027fa4910ba16805e68fddb97
Timeline
08/15/2026 CVE reserved08/22/2026 Advisory disclosed
08/22/2026 VulDB entry created
08/22/2026 VulDB entry last update
Sources
Vendor: kernel.orgAdvisory: git.kernel.org
Status: Confirmed
CVE: CVE-2026-74615 (🔒)
GCVE (CVE): GCVE-0-2026-74615
GCVE (VulDB): GCVE-100-394384
Entry
Created: 08/22/2026 18:05Changes: 08/22/2026 18:05 (59)
Complete: 🔍
Cache ID: 216::103
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