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CVE-2026-64581

Updated on 05 Aug 2026

Severity

7.8 High severity

Details

CVSS score: 7.8
CVSS vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Affected product
Affected component
Links: NIST CIRCL RHEL Ubuntu

Overview

About vulnerability

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

xfrm: fix sk_dst_cache double-free in xfrm_user_policy()

xfrm_user_policy() clears the socket dst cache with __sk_dst_reset(), i.e. the non-atomic __sk_dst_set(sk, NULL): it reads sk_dst_cache with rcu_dereference_protected(), stores NULL and dst_release()s the old dst. That is only safe if no other thread modifies sk_dst_cache concurrently.

For a connected UDP socket that does not hold: the transmit fast path (udp_sendmsg -> sk_dst_check -> sk_dst_reset) 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 dst_release() 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 dst_release Write of size 4 at addr ffff88801897b6c0 by task exploit/155 Call Trace: … dst_release (… ./include/linux/rcuref.h:109) xfrm_user_policy (./include/net/sock.h:2239 ./include/net/sock.h:2256 net/xfrm/xfrm_state.c:3053) do_ip_setsockopt (net/ipv4/ip_sockglue.c:1347) ip_setsockopt (net/ipv4/ip_sockglue.c:1417) do_sock_setsockopt (net/socket.c:2368) __sys_setsockopt (net/socket.c:2393) __x64_sys_setsockopt (net/socket.c:2396) do_syscall_64 (arch/x86/entry/syscall_64.c:94) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)

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

Use the atomic sk_dst_reset() 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.

Details

Affected product:: AlmaLinux 9.2 ESU , Amazon Linux 2 ELS , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , Debian 10 ELS , Debian 11 ELS , Oracle Linux 7 ELS , TuxCare 9.6 ESU , TuxCare 9.8 ESU , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS , Ubuntu 20.04 ELS
Affected packages:: linux @ 4.19.325 (+12 more)

Fixes

Operating system / Project

KernelCare state

Live-patch status from KernelCare for each operating system.

Operating system	Status	Covered kernels
Debian 12	Released	43 kernels 6.1.38-1 6.1.38-2 6.1.38-4 6.1.52-1 6.1.55-1 6.1.64-1 6.1.66-1 6.1.69-1 6.1.76-1 6.1.27-1 6.1.67-1 6.1.85-1 6.1.90-1 6.1.94-1 6.1.99-1 6.1.106-3 6.1.112-1 6.1.115-1 6.1.119-1 6.1.123-1 6.1.128-1 6.1.124-1 6.1.129-1 6.1.133-1 6.1.135-1 6.1.137-1 6.1.140-1 6.1.139-1 6.1.147-1 6.1.148-1 6.1.153-1 6.1.158-1 6.1.159-1 6.1.162-1 6.1.164-1 6.1.170-1 6.1.170-3 6.1.172-1 6.1.174-1 6.1.170-2 6.1.176-1 6.1.177-1 6.1.180-1
Debian 13	Released	16 kernels 6.12.85-1 6.12.86-1 6.12.88-1 6.12.74-2 6.12.73-1 6.12.63-1 6.12.69-1 6.12.74-1 6.12.90-1 6.12.90-2 6.12.94-1 6.12.95-1 6.12.96-1 6.12.100-1 6.12.101-1 6.12.105-1
Oracle Linux 8 UEK 7	In Rollout	114 kernels 5.15.0-102.110.5.el8uek 5.15.0-101.103.2.1.el8uek 5.15.0-8.91.4.1.el8uek 5.15.0-7.86.6.1.el8uek 5.15.0-2.52.3.el8uek 5.15.0-100.96.32.el8uek 5.15.0-5.76.5.1.el8uek 5.15.0-6.80.3.1.el8uek 5.15.0-3.60.5.1.el8uek 5.15.0-0.30.20.el8uek 5.15.0-1.43.4.1.el8uek 5.15.0-0.30.20.1.el8uek 5.15.0-1.43.4.2.el8uek 5.15.0-4.70.5.2.el8uek 5.15.0-104.119.4.2.el8uek 5.15.0-0.30.19.el8uek 5.15.0-105.125.6.2.el8uek 5.15.0-105.125.6.2.1.el8uek 5.15.0-105.125.6.2.2.el8uek 5.15.0-106.131.4.el8uek 5.15.0-200.131.27.el8uek 5.15.0-200.131.27.1.el8uek 5.15.0-201.135.6.el8uek 5.15.0-202.135.2.el8uek 5.15.0-102.110.5.1.el8uek 5.15.0-103.114.4.el8uek 5.15.0-203.146.5.1.el8uek 5.15.0-204.147.6.2.el8uek 5.15.0-204.147.6.3.el8uek 5.15.0-205.149.5.1.el8uek 5.15.0-205.149.5.4.el8uek 5.15.0-206.153.7.el8uek 5.15.0-206.153.7.1.el8uek 5.15.0-207.156.6.el8uek 5.15.0-208.159.3.el8uek 5.15.0-208.159.3.2.el8uek 5.15.0-209.161.7.el8uek 5.15.0-209.161.7.1.el8uek 5.15.0-209.161.7.2.el8uek 5.15.0-210.163.7.el8uek 5.15.0-300.163.18.el8uek 5.15.0-300.163.18.1.el8uek 5.15.0-300.163.18.1.1.el8uek 5.15.0-301.163.5.2.el8uek 5.15.0-302.167.6.el8uek 5.15.0-300.163.18.7.el8uek 5.15.0-302.167.6.1.el8uek 5.15.0-303.171.5.2.el8uek 5.15.0-303.171.5.2.1.el8uek 5.15.0-304.171.4.el8uek 5.15.0-304.171.4.1.el8uek 5.15.0-304.171.4.3.el8uek 5.15.0-303.171.5.2.2.el8uek 5.15.0-305.176.4.el8uek 5.15.0-306.177.4.el8uek 5.15.0-306.177.4.1.el8uek 5.15.0-307.178.5.el8uek 5.15.0-308.179.6.el8uek 5.15.0-308.179.6.2.el8uek 5.15.0-308.179.6.3.el8uek 5.15.0-309.180.4.el8uek 5.15.0-308.179.6.7.el8uek 5.15.0-309.180.4.2.el8uek 5.15.0-308.179.6.11.el8uek 5.15.0-310.184.5.2.el8uek 5.15.0-310.184.5.3.el8uek 5.15.0-311.185.9.el8uek 5.15.0-308.179.6.14.el8uek 5.15.0-312.187.5.el8uek 5.15.0-312.187.5.1.el8uek 5.15.0-312.187.5.2.el8uek 5.15.0-312.187.5.3.el8uek 5.15.0-308.179.6.16.el8uek 5.15.0-313.189.5.1.el8uek 5.15.0-313.189.5.2.el8uek 5.15.0-313.189.5.3.el8uek 5.15.0-314.193.5.3.el8uek 5.15.0-314.193.5.4.el8uek 5.15.0-314.193.5.5.el8uek 5.15.0-315.196.5.1.el8uek 5.15.0-315.196.5.2.el8uek 5.15.0-316.196.4.1.el8uek 5.15.0-316.196.4.2.el8uek 5.15.0-317.197.5.1.el8uek 5.15.0-317.197.5.2.el8uek 5.15.0-318.199.3.2.el8uek 5.15.0-318.199.3.2.1.el8uek 5.15.0-319.201.4.2.el8uek 5.15.0-319.201.4.3.el8uek 5.15.0-319.201.4.4.el8uek 5.15.0-319.201.4.6.el8uek 5.15.0-320.202.8.2.el8uek 5.15.0-320.202.8.3.el8uek 5.15.0-320.202.8.4.el8uek 5.15.0-320.202.8.5.el8uek 5.15.0-318.199.3.6.el8uek 5.15.0-321.202.5.el8uek 5.15.0-321.202.5.1.el8uek 5.15.0-321.202.5.2.el8uek 5.15.0-321.202.5.3.el8uek 5.15.0-322.203.3.2.el8uek 5.15.0-322.203.3.3.el8uek 5.15.0-322.203.3.4.el8uek 5.15.0-322.203.3.4.5.el8uek 5.15.0-308.179.6.18.el8uek 5.15.0-318.199.3.7.el8uek 5.15.0-322.203.3.5.el8uek 5.15.0-322.203.3.4.1.el8uek 5.15.0-323.211.3.3.el8uek 5.15.0-323.211.3.4.el8uek 5.15.0-308.179.6.19.el8uek 5.15.0-323.211.3.5.el8uek 5.15.0-324.217.5.2.el8uek 5.15.0-324.217.5.3.el8uek
Oracle Linux 9 UEK 7	Released	114 kernels 5.15.0-101.103.2.1.el9uek 5.15.0-8.91.4.1.el9uek 5.15.0-7.86.6.1.el9uek 5.15.0-5.76.5.1.el9uek 5.15.0-6.80.3.1.el9uek 5.15.0-3.60.5.1.el9uek 5.15.0-0.30.20.el9uek 5.15.0-100.96.32.el9uek 5.15.0-1.43.4.2.el9uek 5.15.0-2.52.3.el9uek 5.15.0-4.70.5.2.el9uek 5.15.0-1.43.4.1.el9uek 5.15.0-0.30.20.1.el9uek 5.15.0-102.110.5.el9uek 5.15.0-102.110.5.1.el9uek 5.15.0-103.114.4.el9uek 5.15.0-104.119.4.2.el9uek 5.15.0-0.30.19.el9uek 5.15.0-105.125.6.2.el9uek 5.15.0-105.125.6.2.1.el9uek 5.15.0-105.125.6.2.2.el9uek 5.15.0-106.131.4.el9uek 5.15.0-200.131.27.el9uek 5.15.0-200.131.27.1.el9uek 5.15.0-201.135.6.el9uek 5.15.0-202.135.2.el9uek 5.15.0-203.146.5.1.el9uek 5.15.0-204.147.6.2.el9uek 5.15.0-204.147.6.3.el9uek 5.15.0-205.149.5.1.el9uek 5.15.0-205.149.5.4.el9uek 5.15.0-206.153.7.el9uek 5.15.0-206.153.7.1.el9uek 5.15.0-207.156.6.el9uek 5.15.0-208.159.3.el9uek 5.15.0-208.159.3.2.el9uek 5.15.0-209.161.7.el9uek 5.15.0-209.161.7.1.el9uek 5.15.0-209.161.7.2.el9uek 5.15.0-210.163.7.el9uek 5.15.0-300.163.18.el9uek 5.15.0-300.163.18.1.el9uek 5.15.0-300.163.18.1.1.el9uek 5.15.0-301.163.5.2.el9uek 5.15.0-302.167.6.el9uek 5.15.0-300.163.18.7.el9uek 5.15.0-302.167.6.1.el9uek 5.15.0-303.171.5.2.el9uek 5.15.0-303.171.5.2.1.el9uek 5.15.0-304.171.4.el9uek 5.15.0-304.171.4.1.el9uek 5.15.0-304.171.4.3.el9uek 5.15.0-303.171.5.2.2.el9uek 5.15.0-305.176.4.el9uek 5.15.0-306.177.4.el9uek 5.15.0-306.177.4.1.el9uek 5.15.0-307.178.5.el9uek 5.15.0-308.179.6.el9uek 5.15.0-308.179.6.2.el9uek 5.15.0-308.179.6.3.el9uek 5.15.0-309.180.4.el9uek 5.15.0-308.179.6.7.el9uek 5.15.0-309.180.4.2.el9uek 5.15.0-308.179.6.11.el9uek 5.15.0-310.184.5.2.el9uek 5.15.0-310.184.5.3.el9uek 5.15.0-311.185.9.el9uek 5.15.0-308.179.6.14.el9uek 5.15.0-312.187.5.el9uek 5.15.0-312.187.5.1.el9uek 5.15.0-312.187.5.2.el9uek 5.15.0-312.187.5.3.el9uek 5.15.0-308.179.6.16.el9uek 5.15.0-313.189.5.1.el9uek 5.15.0-313.189.5.2.el9uek 5.15.0-313.189.5.3.el9uek 5.15.0-314.193.5.3.el9uek 5.15.0-314.193.5.4.el9uek 5.15.0-314.193.5.5.el9uek 5.15.0-315.196.5.1.el9uek 5.15.0-315.196.5.2.el9uek 5.15.0-316.196.4.1.el9uek 5.15.0-316.196.4.2.el9uek 5.15.0-317.197.5.1.el9uek 5.15.0-317.197.5.2.el9uek 5.15.0-318.199.3.2.el9uek 5.15.0-318.199.3.2.1.el9uek 5.15.0-319.201.4.2.el9uek 5.15.0-319.201.4.3.el9uek 5.15.0-319.201.4.4.el9uek 5.15.0-319.201.4.6.el9uek 5.15.0-320.202.8.2.el9uek 5.15.0-320.202.8.3.el9uek 5.15.0-320.202.8.4.el9uek 5.15.0-320.202.8.5.el9uek 5.15.0-318.199.3.6.el9uek 5.15.0-321.202.5.el9uek 5.15.0-321.202.5.1.el9uek 5.15.0-321.202.5.2.el9uek 5.15.0-321.202.5.3.el9uek 5.15.0-322.203.3.2.el9uek 5.15.0-322.203.3.3.el9uek 5.15.0-322.203.3.4.el9uek 5.15.0-322.203.3.4.5.el9uek 5.15.0-308.179.6.18.el9uek 5.15.0-318.199.3.7.el9uek 5.15.0-322.203.3.5.el9uek 5.15.0-322.203.3.4.1.el9uek 5.15.0-323.211.3.3.el9uek 5.15.0-323.211.3.4.el9uek 5.15.0-308.179.6.19.el9uek 5.15.0-323.211.3.5.el9uek 5.15.0-324.217.5.2.el9uek 5.15.0-324.217.5.3.el9uek
Ubuntu 26.04	Will Not Fix	—

Release info

Copy page link

Open as a page

Advisory

CLSA-2025:1748945064

Operating system

CentOS 8.4 ELS

Published date

Nov 16, 2014

Project

Linux

Version

2.11.0-1~ubuntu16.04.1+tuxcare.els12

How to fix

Update command:

apt-get update
apt-get --only-upgrade install ansible*

Changelog

Insufficiently Random Passwords Leakage
Debian/patches/CVE-2020-10729.patch: Fix caching of Jinja2 expressions to prevent caching dynamic results
CVE-2020-10729

Updated packages

ansible_2.5.1+dfsg-1ubuntu0.1+tuxcare.els6_all.deb

CVE-2026-64581

Severity

Details

Overview

About vulnerability

Details

Statement

Fixes

Statement

KernelCare state

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