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TI-2026-45486 Aliases CVE-2026-63921GHSA-c82w-wxq7-hwv4

ip6: vti: Use ip6_tnl.net in vti6_siocdevprivate().

Priority LOW 39CWE-862Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Security bypass
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 38 fixed, 2 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-862.

Summary

In the Linux kernel, the following vulnerability has been resolved: ip6: vti: Use ip6_tnl.net in vti6_siocdevprivate(). After patch 1/2 in this series, vti6_update() unlinks and relinks the tunnel through t->net. vti6_siocdevprivate() still uses dev_net(dev) for the collision lookup. For a tunnel moved through IFLA_NET_NS_FD, dev_net(dev) is the new netns, not t->net. SIOCCHGTUNNEL on a migrated tunnel then runs: net = dev_net(dev) /* migrated netns */ t = vti6_locate(net, &p1, false) /* misses target in t->net */ ... t = netdev_priv(dev) vti6_update(t, &p1, false) /* mutates t->net's hash */ A caller in the migrated netns picks params that match a tunnel in the creation netns. The lookup in dev_net(dev) finds nothing. vti6_update() prepends the migrated tunnel at the head of the creation netns hash bucket for those params. Later lookups in the creation netns resolve to the migrated device. xfrm receive delivers the matched packets through a device the caller controls. Reachable from an unprivileged user namespace (unshare --user --map-root-user --net). Cross tenant scope on container hosts. Switch the SIOCCHGTUNNEL path on a non fallback device to use t->net for the lookup. The lookup now matches the netns vti6_update() operates on. Also add ns_capable(self->net->user_ns, CAP_NET_ADMIN) before the lookup. The check at the top of the case is against dev_net(dev)->user_ns, which after migration is the attacker's netns. A caller there can pick params absent from self->net, the lookup returns NULL, t becomes self, and vti6_update() inserts the device into the creation netns hash. The new check requires CAP_NET_ADMIN in the creation netns user_ns too. SIOCADDTUNNEL and SIOCCHGTUNNEL on the fallback device keep dev_net(dev), which equals init_net there.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00158 4th percentileScored 2026-11-07
Fix Partial Linux (Linux): 5.10.259, 5.15.210, 6.1.176 +5Red Hat: 12 advisoriesRed Hat: 38 fixed, 2 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
LinuxLinux3.15 and later5.10.259, 5.15.210, 6.1.176, 6.6.143, 6.12.93, 6.18.35, 7.0.12, 7.1Patch availableCNA
  • Linux VendorLinux Affected 3.15 and later Fixed in 5.10.259, 5.15.210, 6.1.176, 6.6.143, 6.12.93, 6.18.35, 7.0.12, 7.1 Patch available CNA

CPE configurations NVD · 6

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*3.15 to before 5.10.259; 5.11 to before 5.15.210; 5.16 to before 6.1.176; 6.2 to before 6.6.143; 6.7 to before 6.12.93; 6.13 to before 6.18.35; 6.19 to before 7.0.12VulnerableLinux
cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*7.1 rc1VulnerableLinux
cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:*7.1 rc2VulnerableLinux
cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:*7.1 rc3VulnerableLinux
cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:*7.1 rc4VulnerableLinux
cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:*7.1 rc5VulnerableLinux
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 3.15 to before 5.10.259; 5.11 to before 5.15.210; 5.16 to before 6.1.176; 6.2 to before 6.6.143; 6.7 to before 6.12.93; 6.13 to before 6.18.35; 6.19 to before 7.0.12 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:* Versions 7.1 rc1 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:* Versions 7.1 rc2 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:* Versions 7.1 rc3 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:* Versions 7.1 rc4 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:* Versions 7.1 rc5 Vulnerable ·Linux

Remediation

  • Fix · CNA Linux (Linux) Fixed in 5.10.259, 5.15.210, 6.1.176, 6.6.143, 6.12.93, 6.18.35, 7.0.12, 7.1

Red Hat 12 advisories

  • RHSA-2026:82860 Released 2026-10-14 · Red Hat rating Important
    kernel-rt security update
    • Red Hat Enterprise Linux Real Time E4S (v.9.2) kernel-rt-5.14.0-284.197.1.rt14.482.el9_2, kernel-rt-core-5.14.0-284.197.1.rt14.482.el9_2, kernel-rt-debug-5.14.0-284.197.1.rt14.482.el9_2 +9
    • Red Hat Enterprise Linux Real Time for NFV E4S (v.9.2) kernel-rt-5.14.0-284.197.1.rt14.482.el9_2, kernel-rt-core-5.14.0-284.197.1.rt14.482.el9_2, kernel-rt-debug-5.14.0-284.197.1.rt14.482.el9_2 +11
  • RHSA-2026:80908 Released 2026-10-12 · Red Hat rating Important
    kernel security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.2) kernel-64k-debug-devel-5.14.0-284.197.1.el9_2, kernel-64k-debug-devel-matched-5.14.0-284.197.1.el9_2, kernel-64k-devel-5.14.0-284.197.1.el9_2 +10
    • Red Hat Enterprise Linux BaseOS E4S (v.9.2) bpftool-7.0.0-284.197.1.el9_2, kernel-5.14.0-284.197.1.el9_2, kernel-64k-5.14.0-284.197.1.el9_2 +29
  • RHSA-2026:77301 Released 2026-10-07 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat Enterprise Linux BaseOS E4S (v.8.8) bpftool-4.18.0-477.172.1.el8_8, kernel-4.18.0-477.172.1.el8_8, kernel-abi-stablelists-4.18.0-477.172.1.el8_8 +14
    • Red Hat Enterprise Linux BaseOS TUS (v.8.8) bpftool-4.18.0-477.172.1.el8_8, kernel-4.18.0-477.172.1.el8_8, kernel-abi-stablelists-4.18.0-477.172.1.el8_8 +14
Show 9 more Red Hat advisories
  • RHSA-2026:77218 Released 2026-10-07 · Red Hat rating Important
    kernel security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.4) kernel-64k-debug-devel-5.14.0-427.154.1.el9_4, kernel-64k-debug-devel-matched-5.14.0-427.154.1.el9_4, kernel-64k-devel-5.14.0-427.154.1.el9_4 +11
    • Red Hat Enterprise Linux BaseOS E4S (v.9.4) bpftool-7.3.0-427.154.1.el9_4, kernel-5.14.0-427.154.1.el9_4, kernel-64k-5.14.0-427.154.1.el9_4 +29
    • Red Hat Enterprise Linux Real Time E4S (v.9.4) kernel-rt-5.14.0-427.154.1.el9_4, kernel-rt-core-5.14.0-427.154.1.el9_4, kernel-rt-debug-5.14.0-427.154.1.el9_4 +9
    • Red Hat Enterprise Linux Real Time for NFV E4S (v.9.4) kernel-rt-5.14.0-427.154.1.el9_4, kernel-rt-core-5.14.0-427.154.1.el9_4, kernel-rt-debug-5.14.0-427.154.1.el9_4 +11
  • RHSA-2026:77217 Released 2026-10-07 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat Enterprise Linux BaseOS AUS (v.8.4) bpftool-4.18.0-305.211.1.el8_4, kernel-4.18.0-305.211.1.el8_4, kernel-abi-stablelists-4.18.0-305.211.1.el8_4 +14
    • Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.4) bpftool-4.18.0-305.211.1.el8_4, kernel-4.18.0-305.211.1.el8_4, kernel-abi-stablelists-4.18.0-305.211.1.el8_4 +19
  • RHSA-2026:77216 Released 2026-10-07 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat Enterprise Linux BaseOS AUS (v.8.6) bpftool-4.18.0-372.220.1.el8_6, kernel-4.18.0-372.220.1.el8_6, kernel-abi-stablelists-4.18.0-372.220.1.el8_6 +14
    • Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6) bpftool-4.18.0-372.220.1.el8_6, kernel-4.18.0-372.220.1.el8_6, kernel-abi-stablelists-4.18.0-372.220.1.el8_6 +19
  • RHSA-2026:75560 Released 2026-10-05 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream EUS (v. 10.0) kernel-64k-debug-devel-6.12.0-55.108.1.el10_0, kernel-64k-debug-devel-matched-6.12.0-55.108.1.el10_0, kernel-64k-devel-6.12.0-55.108.1.el10_0 +12
    • Red Hat Enterprise Linux BaseOS EUS (v. 10.0) kernel-6.12.0-55.108.1.el10_0, kernel-64k-6.12.0-55.108.1.el10_0, kernel-64k-core-6.12.0-55.108.1.el10_0 +28
    • Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) kernel-tools-libs-devel-6.12.0-55.108.1.el10_0, libperf-6.12.0-55.108.1.el10_0
    • Red Hat Enterprise Linux Real Time EUS (v. 10.0) kernel-rt-6.12.0-55.108.1.el10_0, kernel-rt-64k-6.12.0-55.108.1.el10_0, kernel-rt-64k-core-6.12.0-55.108.1.el10_0 +21
    • Red Hat Enterprise Linux Real Time for NFV EUS (v. 10.0) kernel-rt-6.12.0-55.108.1.el10_0, kernel-rt-core-6.12.0-55.108.1.el10_0, kernel-rt-debug-6.12.0-55.108.1.el10_0 +11
  • RHSA-2026:74174 Released 2026-10-01 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat CodeReady Linux Builder EUS (v.9.6) kernel-tools-libs-devel-5.14.0-570.146.1.el9_6, libperf-5.14.0-570.146.1.el9_6
    • Red Hat Enterprise Linux AppStream EUS (v.9.6) kernel-64k-debug-devel-5.14.0-570.146.1.el9_6, kernel-64k-debug-devel-matched-5.14.0-570.146.1.el9_6, kernel-64k-devel-5.14.0-570.146.1.el9_6 +12
    • Red Hat Enterprise Linux BaseOS EUS (v.9.6) kernel-5.14.0-570.146.1.el9_6, kernel-64k-5.14.0-570.146.1.el9_6, kernel-64k-core-5.14.0-570.146.1.el9_6 +28
    • Red Hat Enterprise Linux Real Time EUS (v.9.6) kernel-rt-5.14.0-570.146.1.el9_6, kernel-rt-64k-5.14.0-570.146.1.el9_6, kernel-rt-64k-core-5.14.0-570.146.1.el9_6 +21
    • Red Hat Enterprise Linux Real Time for NFV EUS (v.9.6) kernel-rt-5.14.0-570.146.1.el9_6, kernel-rt-core-5.14.0-570.146.1.el9_6, kernel-rt-debug-5.14.0-570.146.1.el9_6 +11
  • RHSA-2026:68570 Released 2026-09-17 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-687.49.1.el9_8, kernel-64k-debug-devel-matched-5.14.0-687.49.1.el9_8, kernel-64k-devel-5.14.0-687.49.1.el9_8 +12
    • Red Hat Enterprise Linux BaseOS (v. 9) kernel-5.14.0-687.49.1.el9_8, kernel-64k-5.14.0-687.49.1.el9_8, kernel-64k-core-5.14.0-687.49.1.el9_8 +28
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) kernel-tools-libs-devel-5.14.0-687.49.1.el9_8, libperf-5.14.0-687.49.1.el9_8
    • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt-5.14.0-687.49.1.el9_8, kernel-rt-64k-5.14.0-687.49.1.el9_8, kernel-rt-64k-core-5.14.0-687.49.1.el9_8 +21
    • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt-5.14.0-687.49.1.el9_8, kernel-rt-core-5.14.0-687.49.1.el9_8, kernel-rt-debug-5.14.0-687.49.1.el9_8 +9
  • RHSA-2026:68531 Released 2026-09-17 · Red Hat rating Important
    kernel security update
    • Red Hat Enterprise Linux BaseOS (v. 8) bpftool-4.18.0-553.164.1.el8_10, kernel-4.18.0-553.164.1.el8_10, kernel-abi-stablelists-4.18.0-553.164.1.el8_10 +19
    • Red Hat Enterprise Linux CRB (v. 8) kernel-tools-libs-devel-4.18.0-553.164.1.el8_10
  • RHSA-2026:68532 Released 2026-09-17 · Red Hat rating Important
    kernel-rt security update
    • Red Hat Enterprise Linux NFV (v. 8) kernel-rt-4.18.0-553.164.1.rt7.505.el8_10, kernel-rt-core-4.18.0-553.164.1.rt7.505.el8_10, kernel-rt-debug-4.18.0-553.164.1.rt7.505.el8_10 +9
    • Red Hat Enterprise Linux RT (v. 8) kernel-rt-4.18.0-553.164.1.rt7.505.el8_10, kernel-rt-core-4.18.0-553.164.1.rt7.505.el8_10, kernel-rt-debug-4.18.0-553.164.1.rt7.505.el8_10 +7
  • RHSA-2026:67471 Released 2026-09-15 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream (v. 10) kernel-64k-debug-devel-6.12.0-211.55.1.el10_2, kernel-64k-debug-devel-matched-6.12.0-211.55.1.el10_2, kernel-64k-devel-6.12.0-211.55.1.el10_2 +12
    • Red Hat Enterprise Linux BaseOS (v. 10) kernel-6.12.0-211.55.1.el10_2, kernel-64k-6.12.0-211.55.1.el10_2, kernel-64k-core-6.12.0-211.55.1.el10_2 +29
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) kernel-tools-libs-devel-6.12.0-211.55.1.el10_2, libperf-6.12.0-211.55.1.el10_2
    • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt-6.12.0-211.55.1.el10_2, kernel-rt-64k-6.12.0-211.55.1.el10_2, kernel-rt-64k-core-6.12.0-211.55.1.el10_2 +21
    • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt-6.12.0-211.55.1.el10_2, kernel-rt-core-6.12.0-211.55.1.el10_2, kernel-rt-debug-6.12.0-211.55.1.el10_2 +9

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 7AffectedNo fix yet
Red Hat Enterprise Linux 9AffectedNo fix yet
Red Hat CodeReady Linux Builder EUS (v.9.6)Fixed RHSA-2026:74174
Red Hat Enterprise Linux AppStream (v. 10)Fixed RHSA-2026:67471
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2026:68570
Red Hat Enterprise Linux AppStream E4S (v.9.2)Fixed RHSA-2026:80908
Red Hat Enterprise Linux AppStream E4S (v.9.4)Fixed RHSA-2026:77218
Red Hat Enterprise Linux AppStream EUS (v. 10.0)Fixed RHSA-2026:75560
Red Hat Enterprise Linux AppStream EUS (v.9.6)Fixed RHSA-2026:74174
Red Hat Enterprise Linux BaseOS (v. 10)Fixed RHSA-2026:67471
Red Hat Enterprise Linux BaseOS (v. 8)Fixed RHSA-2026:68531
Red Hat Enterprise Linux BaseOS (v. 9)Fixed RHSA-2026:68570
Red Hat Enterprise Linux BaseOS AUS (v.8.4)Fixed RHSA-2026:77217
Red Hat Enterprise Linux BaseOS AUS (v.8.6)Fixed RHSA-2026:77216
Red Hat Enterprise Linux BaseOS E4S (v.8.8)Fixed RHSA-2026:77301
Red Hat Enterprise Linux BaseOS E4S (v.9.2)Fixed RHSA-2026:80908
Red Hat Enterprise Linux BaseOS E4S (v.9.4)Fixed RHSA-2026:77218
Red Hat Enterprise Linux BaseOS EUS (v. 10.0)Fixed RHSA-2026:75560
Red Hat Enterprise Linux BaseOS EUS (v.9.6)Fixed RHSA-2026:74174
Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.4)Fixed RHSA-2026:77217
Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6)Fixed RHSA-2026:77216
Red Hat Enterprise Linux BaseOS TUS (v.8.8)Fixed RHSA-2026:77301
Red Hat Enterprise Linux CRB (v. 8)Fixed RHSA-2026:68531
Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)Fixed RHSA-2026:67471
Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)Fixed RHSA-2026:68570
Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0)Fixed RHSA-2026:75560
Red Hat Enterprise Linux NFV (v. 8)Fixed RHSA-2026:68532
Red Hat Enterprise Linux RT (v. 8)Fixed RHSA-2026:68532
Red Hat Enterprise Linux Real Time (v. 10)Fixed RHSA-2026:67471
Red Hat Enterprise Linux Real Time (v. 9)Fixed RHSA-2026:68570
Red Hat Enterprise Linux Real Time E4S (v.9.2)Fixed RHSA-2026:82860
Red Hat Enterprise Linux Real Time E4S (v.9.4)Fixed RHSA-2026:77218
Red Hat Enterprise Linux Real Time EUS (v. 10.0)Fixed RHSA-2026:75560
Red Hat Enterprise Linux Real Time EUS (v.9.6)Fixed RHSA-2026:74174
Red Hat Enterprise Linux Real Time for NFV (v. 10)Fixed RHSA-2026:67471
Red Hat Enterprise Linux Real Time for NFV (v. 9)Fixed RHSA-2026:68570
Red Hat Enterprise Linux Real Time for NFV E4S (v.9.2)Fixed RHSA-2026:82860
Red Hat Enterprise Linux Real Time for NFV E4S (v.9.4)Fixed RHSA-2026:77218
Red Hat Enterprise Linux Real Time for NFV EUS (v. 10.0)Fixed RHSA-2026:75560
Red Hat Enterprise Linux Real Time for NFV EUS (v.9.6)Fixed RHSA-2026:74174
Not affected: 1 product
  • Red Hat Enterprise Linux 6

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-63921
  2. 2026-10-03 Alias added: GHSA-c82w-wxq7-hwv4
  3. 2026-10-05 Fix available: RHSA-2026:75560 · Red Hat
  4. 2026-10-05 Fix available: Red Hat Enterprise Linux AppStream EUS (v. 10.0), Red Hat Enterprise Linux BaseOS EUS (v. 10.0), Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) +2 · Red Hat
  5. 2026-10-07 Fix available: RHSA-2026:77216 · Red Hat
  6. 2026-10-07 Fix available: Red Hat Enterprise Linux BaseOS AUS (v.8.6), Red Hat Enterprise Linux BaseOS E4S (v.8.8), Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6) +1 · Red Hat
  7. 2026-10-07 Fix available: RHSA-2026:77301 · Red Hat
  8. 2026-10-07 Fix available: RHSA-2026:77218 · Red Hat
  9. 2026-10-07 Fix available: RHSA-2026:77217 · Red Hat
  10. 2026-10-07 Fix available: Red Hat Enterprise Linux AppStream E4S (v.9.4), Red Hat Enterprise Linux BaseOS AUS (v.8.4), Red Hat Enterprise Linux BaseOS E4S (v.9.4) +3 · Red Hat
  11. 2026-10-13 Fix available: RHSA-2026:80908 · Red Hat
  12. 2026-10-13 Fix available: Red Hat Enterprise Linux AppStream E4S (v.9.2), Red Hat Enterprise Linux BaseOS E4S (v.9.2) · Red Hat
  13. 2026-10-15 Fix available: RHSA-2026:82860 · Red Hat
  14. 2026-10-16 Fix available: Red Hat Enterprise Linux Real Time E4S (v.9.2), Red Hat Enterprise Linux Real Time for NFV E4S (v.9.2) · Red Hat
  15. 2026-10-16 CISA SSVC decision points changed
  16. 2026-10-19 Weakness changed · CISA ADP

References

Patch 8

  • TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
  • TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
  • TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
  • TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
  • TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
  • TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
See all 15278 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences