Linux Kernel up to 7.1-rc2 ip6_gre net/core/dev.c ip6erspan_changelink use after free

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7.7	$0-$5k	0.00

Summaryinfo

A vulnerability classified as critical was found in Linux Kernel up to 6.6.139/6.12.87/6.18.29/7.0.6/7.1-rc2. The impacted element is the function ip6erspan_changelink of the file net/core/dev.c of the component ip6_gre. Executing a manipulation can lead to use after free. The identification of this vulnerability is CVE-2026-46120. There is no exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.6.139/6.12.87/6.18.29/7.0.6/7.1-rc2. It has been declared as critical. This vulnerability affects the function ip6erspan_changelink of the file net/core/dev.c of the component ip6_gre. 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: ip6_gre: Use cached t->net in ip6erspan_changelink(). After commit 5e72ce3e3980 ("net: ipv6: Use link netns in newlink() of rtnl_link_ops"), ip6erspan_newlink() correctly resolves the per-netns ip6gre hash via link_net. ip6erspan_changelink() was not converted in that series and still uses dev_net(dev), which diverges from the device's creation netns after IFLA_NET_NS_FD migration. This re-inserts the tunnel into the wrong per-netns hash. The original netns keeps a stale entry. When that netns is later destroyed, ip6gre_exit_rtnl_net() walks the stale entry, producing a slab-use-after-free reported by KASAN, followed by a kernel BUG at net/core/dev.c (LIST_POISON1) in unregister_netdevice_many_notify(). Reachable from an unprivileged user namespace (unshare --user --map-root-user --net). ip6gre_changelink() earlier in the same file already uses the cached t->net; only ip6erspan_changelink() has the wrong shape.

The weakness was shared by KASAN and followed. The advisory is shared for download at git.kernel.org. This vulnerability was named CVE-2026-46120 since 05/13/2026. The exploitation appears to be easy. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 06/27/2026).

The vulnerability scanner Nessus provides a plugin with the ID 323249 (SUSE SLES15: cluster-md-kmp-default / dlm-kmp-default / gfs2-kmp-default / etc (SUSE-SU-2026:2658-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.6.140, 6.12.88, 6.18.30, 7.0.7 or 7.1-rc3 eliminates this vulnerability. Applying the patch eca62bb0569de4d43a4dac06a2092a9d4ca1d702/311fdd26eb4443d43b909cc67a10f3a5fd1b21b2/e70cfb40c3a99b232cd42c6a6a10f0d8e039dc82/cf7fc624329e76c6394653d12353e1d033adea91/1d324c2f43f70c965f25c58cc3611c779adbe47e is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at Tenable (323249). Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.6.139
• 6.12.0
• 6.12.1
• 6.12.2
• 6.12.3
• 6.12.4
• 6.12.5
• 6.12.6
• 6.12.7
• 6.12.8
• 6.12.9
• 6.12.10
• 6.12.11
• 6.12.12
• 6.12.13
• 6.12.14
• 6.12.15
• 6.12.16
• 6.12.17
• 6.12.18
• 6.12.19
• 6.12.20
• 6.12.21
• 6.12.22
• 6.12.23
• 6.12.24
• 6.12.25
• 6.12.26
• 6.12.27
• 6.12.28
• 6.12.29
• 6.12.30
• 6.12.31
• 6.12.32
• 6.12.33
• 6.12.34
• 6.12.35
• 6.12.36
• 6.12.37
• 6.12.38
• 6.12.39
• 6.12.40
• 6.12.41
• 6.12.42
• 6.12.43
• 6.12.44
• 6.12.45
• 6.12.46
• 6.12.47
• 6.12.48
• 6.12.49
• 6.12.50
• 6.12.51
• 6.12.52
• 6.12.53
• 6.12.54
• 6.12.55
• 6.12.56
• 6.12.57
• 6.12.58
• 6.12.59
• 6.12.60
• 6.12.61
• 6.12.62
• 6.12.63
• 6.12.64
• 6.12.65
• 6.12.66
• 6.12.67
• 6.12.68
• 6.12.69
• 6.12.70
• 6.12.71
• 6.12.72
• 6.12.73
• 6.12.74
• 6.12.75
• 6.12.76
• 6.12.77
• 6.12.78
• 6.12.79
• 6.12.80
• 6.12.81
• 6.12.82
• 6.12.83
• 6.12.84
• 6.12.85
• 6.12.86
• 6.12.87
• 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
• 7.0.0
• 7.0.1
• 7.0.2
• 7.0.3
• 7.0.4
• 7.0.5
• 7.0.6
• 7.1-rc1
• 7.1-rc2

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.9
VulDB Meta Temp Score: 7.7

VulDB Base Score: 8.0
VulDB Temp Score: 7.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 7.8
CNA Vector (Linux): 🔒

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

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

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Nessus ID: 323249
Nessus Name: SUSE SLES15: cluster-md-kmp-default / dlm-kmp-default / gfs2-kmp-default / etc (SUSE-SU-2026:2658-1)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.6.140/6.12.88/6.18.30/7.0.7/7.1-rc3
Patch: eca62bb0569de4d43a4dac06a2092a9d4ca1d702/311fdd26eb4443d43b909cc67a10f3a5fd1b21b2/e70cfb40c3a99b232cd42c6a6a10f0d8e039dc82/cf7fc624329e76c6394653d12353e1d033adea91/1d324c2f43f70c965f25c58cc3611c779adbe47e

Timelineinfo

05/13/2026 CVE reserved
05/28/2026 +15 days Advisory disclosed
05/28/2026 +0 days VulDB entry created
06/27/2026 +30 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Researcher: KASAN, followed
Status: Confirmed

CVE: CVE-2026-46120 (🔒)
GCVE (CVE): GCVE-0-2026-46120
GCVE (VulDB): GCVE-100-366604

Entryinfo

Created: 05/28/2026 13:01
Updated: 06/27/2026 19:58
Changes: 05/28/2026 13:01 (61), 06/25/2026 02:58 (11), 06/27/2026 19:58 (2)
Complete: 🔍
Cache ID: 216::103

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