CVE-2026-64581

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Source
https://cve.org/CVERecord?id=CVE-2026-64581
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64581.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-64581
Downstream
Published
2026-08-05T08:09:35.556Z
Modified
2026-08-09T03:31:36.115352429Z
Severity
  • 7.8 (High) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
Summary
xfrm: fix sk_dst_cache double-free in xfrm_user_policy()
Details

In the Linux kernel, the following vulnerability has been resolved:

xfrm: fix skdstcache double-free in xfrmuserpolicy()

xfrmuserpolicy() clears the socket dst cache with __skdstreset(), i.e. the non-atomic _skdstset(sk, NULL): it reads skdstcache with rcudereferenceprotected(), stores NULL and dstrelease()s the old dst. That is only safe if no other thread modifies skdstcache concurrently.

For a connected UDP socket that does not hold: the transmit fast path (udpsendmsg -> skdstcheck -> skdstreset) resets the cache locklessly with an atomic xchg(). A per-socket policy change racing a send can make both sides observe the same old dst and each dstrelease() it, dropping the socket's single reference twice and freeing the xfrm_dst bundle while it is still referenced:

BUG: KASAN: slab-use-after-free in dstrelease Write of size 4 at addr ffff88801897b6c0 by task exploit/155 Call Trace: ... dstrelease (... ./include/linux/rcuref.h:109) xfrmuserpolicy (./include/net/sock.h:2239 ./include/net/sock.h:2256 net/xfrm/xfrmstate.c:3053) doipsetsockopt (net/ipv4/ipsockglue.c:1347) ipsetsockopt (net/ipv4/ipsockglue.c:1417) dosocksetsockopt (net/socket.c:2368) __sys_setsockopt (net/socket.c:2393) __x64syssetsockopt (net/socket.c:2396) dosyscall64 (arch/x86/entry/syscall64.c:94) entrySYSCALL64afterhwframe (arch/x86/entry/entry64.S:121)

Reachable by an unprivileged user via a user+network namespace.

Use the atomic skdstreset() so the cache is cleared and released with a single xchg(): whichever side wins releases the dst once, the other sees NULL and does nothing. Behaviour is otherwise unchanged.

Database specific 
{
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64581.json",
    "cna_assigner": "Linux"
}
References

Affected packages

Git / git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Affected ranges

Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
2b06cdf3e688b98fcc9945873b5d42792bd4eee0
Fixed
96b678d08268b5f5c6fc99d4289d9b7e334fc683
Fixed
c283e9ada7fcb7dd4b10592623086b2e6d2f9925
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Last affected
72f157be2f81910ae759bfe2e5c2256fc4625645
Last affected
9e9fe58a92a46c6d154d2901735bf230d91b8507
Last affected
adc1ec6cdc20d430aa01b86497220709b9149466
Last affected
b54033eb1cfd77aba471269ddd804ed8d3e35dea
Last affected
c9e82cb34c3c2ee895af01bc899c6ed0bc6eb04a
Last affected
5eef9b51114fcc65651d671add52f267f91b9451
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
3.16.52
Fixed
3.17
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
4.4.163
Fixed
4.5
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
3.18.101
Fixed
3.19
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
4.1.52
Fixed
4.2
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
4.4.123
Fixed
4.5
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
4.9.89
Fixed
4.10

Affected versions

v2.*
v2.6.12-rc2
v2.6.12-rc3
v2.6.12-rc4
v2.6.13
v2.6.13-rc1
v2.6.13-rc2
v2.6.13-rc3
v2.6.13-rc4
v2.6.13-rc5
v2.6.13-rc6
v2.6.13-rc7
v2.6.14-rc1
v2.6.14-rc2
v2.6.14-rc3
v2.6.15-rc1
v2.6.15-rc2
v2.6.15-rc4
v2.6.15-rc5
v2.6.15-rc7
v2.6.16
v2.6.16-rc1
v2.6.16-rc2
v2.6.16-rc3
v2.6.16-rc4
v2.6.16-rc5
v2.6.16-rc6
v2.6.17
v2.6.17-rc1
v2.6.17-rc2
v2.6.17-rc3
v2.6.17-rc4
v2.6.17-rc5
v2.6.17-rc6
v2.6.18
v2.6.18-rc1
v2.6.18-rc2
v2.6.18-rc3
v2.6.18-rc5
v2.6.18-rc6
v2.6.19-rc1
v2.6.19-rc2
v2.6.20-rc1
v2.6.20-rc2
v2.6.20-rc3
v2.6.20-rc4
v2.6.20-rc5
v2.6.20-rc6
v2.6.20-rc7
v2.6.21
v2.6.21-rc1
v2.6.21-rc2
v2.6.21-rc3
v2.6.21-rc4
v2.6.21-rc5
v2.6.21-rc6
v2.6.21-rc7
v2.6.22
v2.6.22-rc1
v2.6.22-rc2
v2.6.22-rc3
v2.6.22-rc4
v2.6.22-rc5
v2.6.22-rc6
v2.6.22-rc7
v2.6.23
v2.6.23-rc1
v2.6.23-rc2
v2.6.23-rc3
v2.6.23-rc4
v2.6.23-rc5
v2.6.23-rc6
v2.6.23-rc7
v2.6.23-rc8
v2.6.23-rc9
v2.6.24
v2.6.24-rc1
v2.6.24-rc2
v2.6.24-rc3
v2.6.24-rc4
v2.6.24-rc5
v2.6.24-rc6
v2.6.24-rc7
v2.6.24-rc8
v2.6.25
v2.6.25-rc1
v2.6.25-rc2
v2.6.25-rc3
v2.6.25-rc4
v2.6.25-rc5
v2.6.25-rc6
v2.6.25-rc7
v2.6.25-rc8
v2.6.25-rc9
v2.6.26
v2.6.26-rc1
v2.6.26-rc2
v2.6.26-rc3
v2.6.26-rc4
v2.6.26-rc5
v2.6.26-rc6
v2.6.26-rc7
v2.6.26-rc8
v2.6.26-rc9
v2.6.27
v2.6.27-rc1
v2.6.27-rc2
v2.6.27-rc3
v2.6.27-rc4
v2.6.27-rc5
v2.6.27-rc6
v2.6.27-rc7
v2.6.27-rc8
v2.6.27-rc9
v2.6.28
v2.6.28-rc1
v2.6.28-rc2
v2.6.28-rc3
v2.6.28-rc4
v2.6.28-rc5
v2.6.28-rc6
v2.6.28-rc7
v2.6.28-rc8
v2.6.28-rc9
v2.6.29
v2.6.29-rc1
v2.6.29-rc2
v2.6.29-rc3
v2.6.29-rc4
v2.6.29-rc5
v2.6.29-rc6
v2.6.29-rc7
v2.6.29-rc8
v2.6.30
v2.6.30-rc1
v2.6.30-rc2
v2.6.30-rc3
v2.6.30-rc4
v2.6.30-rc5
v2.6.30-rc6
v2.6.30-rc7
v2.6.30-rc8
v2.6.31
v2.6.31-rc1
v2.6.31-rc2
v2.6.31-rc3
v2.6.31-rc4
v2.6.31-rc5
v2.6.31-rc6
v2.6.31-rc7
v2.6.31-rc8
v2.6.31-rc9
v2.6.32
v2.6.32-rc1
v2.6.32-rc2
v2.6.32-rc3
v2.6.32-rc4
v2.6.32-rc5
v2.6.32-rc6
v2.6.32-rc7
v2.6.32-rc8
v2.6.33
v2.6.33-rc1
v2.6.33-rc2
v2.6.33-rc3
v2.6.33-rc4
v2.6.33-rc5
v2.6.33-rc6
v2.6.33-rc7
v2.6.33-rc8
v2.6.34
v2.6.34-rc1
v2.6.34-rc2
v2.6.34-rc3
v2.6.34-rc4
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v2.6.35
v2.6.35-rc1
v2.6.35-rc2
v2.6.35-rc3
v2.6.35-rc4
v2.6.35-rc5
v2.6.35-rc6
v2.6.36
v2.6.36-rc1
v2.6.36-rc2
v2.6.36-rc3
v2.6.36-rc4
v2.6.36-rc5
v2.6.36-rc6
v2.6.36-rc7
v2.6.36-rc8
v2.6.37
v2.6.37-rc1
v2.6.37-rc2
v2.6.37-rc3
v2.6.37-rc4
v2.6.37-rc5
v2.6.37-rc6
v2.6.37-rc7
v2.6.37-rc8
v2.6.38
v2.6.38-rc1
v2.6.38-rc2
v2.6.38-rc3
v2.6.38-rc4
v2.6.38-rc5
v2.6.38-rc6
v2.6.38-rc7
v2.6.38-rc8
v2.6.39
v2.6.39-rc1
v2.6.39-rc2
v2.6.39-rc3
v2.6.39-rc4
v2.6.39-rc5
v2.6.39-rc6
v2.6.39-rc7
v3.*
v3.0
v3.0-rc1
v3.0-rc2
v3.0-rc3
v3.0-rc4
v3.0-rc5
v3.0-rc6
v3.0-rc7
v3.1
v3.1-rc1
v3.1-rc10
v3.1-rc2
v3.1-rc3
v3.1-rc4
v3.1-rc5
v3.1-rc6
v3.1-rc7
v3.1-rc8
v3.1-rc9
v3.10
v3.10-rc1
v3.10-rc2
v3.10-rc3
v3.10-rc4
v3.10-rc5
v3.10-rc6
v3.10-rc7
v3.11
v3.11-rc1
v3.11-rc2
v3.11-rc3
v3.11-rc4
v3.11-rc5
v3.11-rc6
v3.11-rc7
v3.12
v3.12-rc1
v3.12-rc2
v3.12-rc3
v3.12-rc4
v3.12-rc5
v3.12-rc6
v3.12-rc7
v3.13
v3.13-rc1
v3.13-rc2
v3.13-rc3
v3.13-rc4
v3.13-rc5
v3.13-rc6
v3.13-rc7
v3.13-rc8
v3.14
v3.14-rc1
v3.14-rc2
v3.14-rc3
v3.14-rc4
v3.14-rc5
v3.14-rc6
v3.14-rc7
v3.14-rc8
v3.15
v3.15-rc1
v3.15-rc2
v3.15-rc3
v3.15-rc4
v3.15-rc5
v3.15-rc6
v3.15-rc7
v3.15-rc8
v3.16
v3.16-rc1
v3.16-rc2
v3.16-rc3
v3.16-rc4
v3.16-rc5
v3.16-rc6
v3.16-rc7
v3.16.1
v3.16.2
v3.16.3
v3.16.35
v3.16.36
v3.16.37
v3.16.38
v3.16.39
v3.16.4
v3.16.40
v3.16.41
v3.16.42
v3.16.43
v3.16.44
v3.16.45
v3.16.46
v3.16.47
v3.16.48
v3.16.49
v3.16.5
v3.16.50
v3.16.51
v3.16.6
v3.16.7
v3.17
v3.17-rc1
v3.17-rc2
v3.17-rc3
v3.17-rc4
v3.17-rc5
v3.17-rc6
v3.17-rc7
v3.18
v3.18-rc1
v3.18-rc2
v3.18-rc3
v3.18-rc4
v3.18-rc5
v3.18-rc6
v3.18-rc7
v3.18.1
v3.18.10
v3.18.100
v3.18.11
v3.18.12
v3.18.13
v3.18.14
v3.18.15
v3.18.16
v3.18.17
v3.18.18
v3.18.19
v3.18.2
v3.18.20
v3.18.21
v3.18.22
v3.18.23
v3.18.24
v3.18.25
v3.18.26
v3.18.27
v3.18.28
v3.18.29
v3.18.3
v3.18.30
v3.18.31
v3.18.32
v3.18.33
v3.18.34
v3.18.35
v3.18.36
v3.18.37
v3.18.38
v3.18.39
v3.18.4
v3.18.40
v3.18.41
v3.18.42
v3.18.43
v3.18.44
v3.18.45
v3.18.46
v3.18.47
v3.18.48
v3.18.49
v3.18.5
v3.18.50
v3.18.51
v3.18.52
v3.18.53
v3.18.54
v3.18.55
v3.18.56
v3.18.57
v3.18.58
v3.18.59
v3.18.6
v3.18.60
v3.18.61
v3.18.62
v3.18.63
v3.18.64
v3.18.65
v3.18.66
v3.18.67
v3.18.68
v3.18.69
v3.18.7
v3.18.70
v3.18.71
v3.18.72
v3.18.73
v3.18.74
v3.18.75
v3.18.76
v3.18.77
v3.18.78
v3.18.79
v3.18.8
v3.18.80
v3.18.81
v3.18.82
v3.18.83
v3.18.84
v3.18.85
v3.18.86
v3.18.87
v3.18.88
v3.18.89
v3.18.9
v3.18.90
v3.18.91
v3.18.92
v3.18.93
v3.18.94
v3.18.95
v3.18.96
v3.18.97
v3.18.98
v3.18.99
v3.19
v3.19-rc1
v3.19-rc2
v3.19-rc3
v3.19-rc4
v3.19-rc5
v3.19-rc6
v3.19-rc7
v3.2
v3.2-rc1
v3.2-rc2
v3.2-rc3
v3.2-rc4
v3.2-rc5
v3.2-rc6
v3.2-rc7
v3.3
v3.3-rc1
v3.3-rc2
v3.3-rc3
v3.3-rc4
v3.3-rc5
v3.3-rc6
v3.3-rc7
v3.4
v3.4-rc1
v3.4-rc2
v3.4-rc3
v3.4-rc4
v3.4-rc5
v3.4-rc6
v3.4-rc7
v3.5
v3.5-rc1
v3.5-rc2
v3.5-rc3
v3.5-rc4
v3.5-rc5
v3.5-rc6
v3.5-rc7
v3.6
v3.6-rc1
v3.6-rc2
v3.6-rc3
v3.6-rc4
v3.6-rc5
v3.6-rc6
v3.6-rc7
v3.7
v3.7-rc1
v3.7-rc2
v3.7-rc3
v3.7-rc4
v3.7-rc5
v3.7-rc6
v3.7-rc7
v3.7-rc8
v3.8
v3.8-rc1
v3.8-rc2
v3.8-rc3
v3.8-rc4
v3.8-rc5
v3.8-rc6
v3.8-rc7
v3.9
v3.9-rc1
v3.9-rc2
v3.9-rc3
v3.9-rc4
v3.9-rc5
v3.9-rc6
v3.9-rc7
v3.9-rc8
v4.*
v4.0
v4.0-rc1
v4.0-rc2
v4.0-rc3
v4.0-rc4
v4.0-rc5
v4.0-rc6
v4.0-rc7
v4.1
v4.1-rc1
v4.1-rc2
v4.1-rc3
v4.1-rc4
v4.1-rc5
v4.1-rc6
v4.1-rc7
v4.1-rc8
v4.1.1
v4.1.10
v4.1.11
v4.1.12
v4.1.13
v4.1.14
v4.1.15
v4.1.16
v4.1.17
v4.1.18
v4.1.19
v4.1.2
v4.1.20
v4.1.21
v4.1.22
v4.1.23
v4.1.24
v4.1.25
v4.1.26
v4.1.27
v4.1.28
v4.1.29
v4.1.3
v4.1.30
v4.1.31
v4.1.32
v4.1.33
v4.1.34
v4.1.35
v4.1.36
v4.1.37
v4.1.38
v4.1.39
v4.1.4
v4.1.40
v4.1.41
v4.1.42
v4.1.43
v4.1.44
v4.1.45
v4.1.46
v4.1.47
v4.1.48
v4.1.49
v4.1.5
v4.1.50
v4.1.51
v4.1.6
v4.1.7
v4.1.8
v4.1.9
v4.2
v4.2-rc1
v4.2-rc2
v4.2-rc3
v4.2-rc4
v4.2-rc5
v4.2-rc6
v4.2-rc7
v4.2-rc8
v4.3
v4.3-rc1
v4.3-rc2
v4.3-rc3
v4.3-rc4
v4.3-rc5
v4.3-rc6
v4.3-rc7
v4.4
v4.4-rc1
v4.4-rc2
v4.4-rc3
v4.4-rc4
v4.4-rc5
v4.4-rc6
v4.4-rc7
v4.4-rc8
v4.4.1
v4.4.10
v4.4.100
v4.4.101
v4.4.102
v4.4.103
v4.4.104
v4.4.105
v4.4.106
v4.4.107
v4.4.108
v4.4.109
v4.4.11
v4.4.110
v4.4.111
v4.4.112
v4.4.113
v4.4.114
v4.4.115
v4.4.116
v4.4.117
v4.4.118
v4.4.119
v4.4.12
v4.4.120
v4.4.121
v4.4.122
v4.4.123
v4.4.124
v4.4.125
v4.4.126
v4.4.127
v4.4.128
v4.4.129
v4.4.13
v4.4.130
v4.4.131
v4.4.132
v4.4.133
v4.4.134
v4.4.135
v4.4.136
v4.4.137
v4.4.138
v4.4.139
v4.4.14
v4.4.140
v4.4.141
v4.4.142
v4.4.143
v4.4.144
v4.4.145
v4.4.146
v4.4.147
v4.4.148
v4.4.149
v4.4.15
v4.4.150
v4.4.151
v4.4.152
v4.4.153
v4.4.154
v4.4.155
v4.4.156
v4.4.157
v4.4.158
v4.4.159
v4.4.16
v4.4.160
v4.4.161
v4.4.162
v4.4.17
v4.4.18
v4.4.19
v4.4.2
v4.4.20
v4.4.21
v4.4.22
v4.4.23
v4.4.24
v4.4.25
v4.4.26
v4.4.27
v4.4.28
v4.4.29
v4.4.3
v4.4.30
v4.4.31
v4.4.32
v4.4.33
v4.4.34
v4.4.35
v4.4.36
v4.4.37
v4.4.38
v4.4.39
v4.4.4
v4.4.40
v4.4.41
v4.4.42
v4.4.43
v4.4.44
v4.4.45
v4.4.46
v4.4.47
v4.4.48
v4.4.49
v4.4.5
v4.4.50
v4.4.51
v4.4.52
v4.4.53
v4.4.54
v4.4.55
v4.4.56
v4.4.57
v4.4.58
v4.4.59
v4.4.6
v4.4.60
v4.4.61
v4.4.62
v4.4.63
v4.4.64
v4.4.65
v4.4.66
v4.4.67
v4.4.68
v4.4.69
v4.4.7
v4.4.70
v4.4.71
v4.4.72
v4.4.73
v4.4.74
v4.4.75
v4.4.76
v4.4.77
v4.4.78
v4.4.79
v4.4.8
v4.4.80
v4.4.81
v4.4.82
v4.4.83
v4.4.84
v4.4.85
v4.4.86
v4.4.87
v4.4.88
v4.4.89
v4.4.9
v4.4.90
v4.4.91
v4.4.92
v4.4.93
v4.4.94
v4.4.95
v4.4.96
v4.4.97
v4.4.98
v4.4.99
v4.5
v4.5-rc1
v4.5-rc2
v4.5-rc3
v4.5-rc4
v4.5-rc5
v4.5-rc6
v4.5-rc7
v4.6
v4.6-rc1
v4.6-rc2
v4.6-rc3
v4.6-rc4
v4.6-rc5
v4.6-rc6
v4.6-rc7
v4.7
v4.7-rc1
v4.7-rc2
v4.7-rc3
v4.7-rc4
v4.7-rc5
v4.7-rc6
v4.7-rc7
v4.8
v4.8-rc1
v4.8-rc2
v4.8-rc3
v4.8-rc4
v4.8-rc5
v4.8-rc6
v4.8-rc7
v4.8-rc8
v4.9
v4.9-rc1
v4.9-rc2
v4.9-rc3
v4.9-rc4
v4.9-rc5
v4.9-rc6
v4.9-rc7
v4.9-rc8
v4.9.1
v4.9.10
v4.9.11
v4.9.12
v4.9.13
v4.9.14
v4.9.15
v4.9.16
v4.9.17
v4.9.18
v4.9.19
v4.9.2
v4.9.20
v4.9.21
v4.9.22
v4.9.23
v4.9.24
v4.9.25
v4.9.26
v4.9.27
v4.9.28
v4.9.29
v4.9.3
v4.9.30
v4.9.31
v4.9.32
v4.9.33
v4.9.34
v4.9.35
v4.9.36
v4.9.37
v4.9.38
v4.9.39
v4.9.4
v4.9.40
v4.9.41
v4.9.42
v4.9.43
v4.9.44
v4.9.45
v4.9.46
v4.9.47
v4.9.48
v4.9.49
v4.9.5
v4.9.50
v4.9.51
v4.9.52
v4.9.53
v4.9.54
v4.9.55
v4.9.56
v4.9.57
v4.9.58
v4.9.59
v4.9.6
v4.9.60
v4.9.61
v4.9.62
v4.9.63
v4.9.64
v4.9.65
v4.9.66
v4.9.67
v4.9.68
v4.9.69
v4.9.7
v4.9.70
v4.9.71
v4.9.72
v4.9.73
v4.9.74
v4.9.75
v4.9.76
v4.9.77
v4.9.78
v4.9.79
v4.9.8
v4.9.80
v4.9.81
v4.9.82
v4.9.83
v4.9.84
v4.9.85
v4.9.86
v4.9.87
v4.9.88
v4.9.9

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64581.json"

Linux / Kernel

Package

Name
Kernel

Affected ranges

Type
ECOSYSTEM
Events
Introduced
4.14.0
Fixed
7.1.6

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64581.json"