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TI-2026-45558 Aliases CVE-2026-63993GHSA-p6vc-4hvx-xvcw

vxlan: do not reuse cached ip_hdr() value after skb_tunnel_check_pmtu()

Priority MEDIUM 49CWE-416Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 28 fixed, 1 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-416 and the CVSS impact.

Summary

In the Linux kernel, the following vulnerability has been resolved: vxlan: do not reuse cached ip_hdr() value after skb_tunnel_check_pmtu() skb_tunnel_check_pmtu() can change skb->head. Reusing old_iph afer skb_tunnel_check_pmtu() can cause an UAF. Use instead ip_hdr(skb) as done in drivers/net/bareudp.c and drivers/net/geneve.c. Found by Sashiko.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00514 44th percentileScored 2026-11-07
Fix Partial Linux (Linux): 5.10.259, 5.15.210, 6.1.176 +5Red Hat: 7 advisoriesRed Hat: 28 fixed, 1 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
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
LinuxLinux5.9 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 5.9 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:*:*:*:*:*:*:*:*5.9 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 5.9 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 7 advisories

  • RHSA-2026:93047 Released 2026-10-30 · Red Hat rating Important
    kernel-rt security, bug fix, and enhancement update
    • Red Hat Enterprise Linux Real Time E4S (v.9.2) kernel-rt-5.14.0-284.200.1.rt14.485.el9_2, kernel-rt-core-5.14.0-284.200.1.rt14.485.el9_2, kernel-rt-debug-5.14.0-284.200.1.rt14.485.el9_2 +9
    • Red Hat Enterprise Linux Real Time for NFV E4S (v.9.2) kernel-rt-5.14.0-284.200.1.rt14.485.el9_2, kernel-rt-core-5.14.0-284.200.1.rt14.485.el9_2, kernel-rt-debug-5.14.0-284.200.1.rt14.485.el9_2 +11
  • RHSA-2026:92993 Released 2026-10-30 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream E4S (v.9.2) kernel-64k-debug-devel-5.14.0-284.200.1.el9_2, kernel-64k-debug-devel-matched-5.14.0-284.200.1.el9_2, kernel-64k-devel-5.14.0-284.200.1.el9_2 +10
    • Red Hat Enterprise Linux BaseOS E4S (v.9.2) bpftool-7.0.0-284.200.1.el9_2, kernel-5.14.0-284.200.1.el9_2, kernel-64k-5.14.0-284.200.1.el9_2 +29
  • RHSA-2026:91492 Released 2026-10-28 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat CodeReady Linux Builder EUS (v.9.6) kernel-tools-libs-devel-5.14.0-570.152.1.el9_6, libperf-5.14.0-570.152.1.el9_6
    • Red Hat Enterprise Linux AppStream EUS (v.9.6) kernel-64k-debug-devel-5.14.0-570.152.1.el9_6, kernel-64k-debug-devel-matched-5.14.0-570.152.1.el9_6, kernel-64k-devel-5.14.0-570.152.1.el9_6 +12
    • Red Hat Enterprise Linux BaseOS EUS (v.9.6) kernel-5.14.0-570.152.1.el9_6, kernel-64k-5.14.0-570.152.1.el9_6, kernel-64k-core-5.14.0-570.152.1.el9_6 +28
    • Red Hat Enterprise Linux Real Time EUS (v.9.6) kernel-rt-5.14.0-570.152.1.el9_6, kernel-rt-64k-5.14.0-570.152.1.el9_6, kernel-rt-64k-core-5.14.0-570.152.1.el9_6 +21
    • Red Hat Enterprise Linux Real Time for NFV EUS (v.9.6) kernel-rt-5.14.0-570.152.1.el9_6, kernel-rt-core-5.14.0-570.152.1.el9_6, kernel-rt-debug-5.14.0-570.152.1.el9_6 +11
Show 4 more Red Hat advisories
  • RHSA-2026:91489 Released 2026-10-28 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream E4S (v.9.4) kernel-64k-debug-devel-5.14.0-427.158.1.el9_4, kernel-64k-debug-devel-matched-5.14.0-427.158.1.el9_4, kernel-64k-devel-5.14.0-427.158.1.el9_4 +11
    • Red Hat Enterprise Linux BaseOS E4S (v.9.4) bpftool-7.3.0-427.158.1.el9_4, kernel-5.14.0-427.158.1.el9_4, kernel-64k-5.14.0-427.158.1.el9_4 +29
    • Red Hat Enterprise Linux Real Time E4S (v.9.4) kernel-rt-5.14.0-427.158.1.el9_4, kernel-rt-core-5.14.0-427.158.1.el9_4, kernel-rt-debug-5.14.0-427.158.1.el9_4 +9
    • Red Hat Enterprise Linux Real Time for NFV E4S (v.9.4) kernel-rt-5.14.0-427.158.1.el9_4, kernel-rt-core-5.14.0-427.158.1.el9_4, kernel-rt-debug-5.14.0-427.158.1.el9_4 +11
  • RHSA-2026:83707 Released 2026-10-16 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream EUS (v. 10.0) kernel-64k-debug-devel-6.12.0-55.111.1.el10_0, kernel-64k-debug-devel-matched-6.12.0-55.111.1.el10_0, kernel-64k-devel-6.12.0-55.111.1.el10_0 +12
    • Red Hat Enterprise Linux BaseOS EUS (v. 10.0) kernel-6.12.0-55.111.1.el10_0, kernel-64k-6.12.0-55.111.1.el10_0, kernel-64k-core-6.12.0-55.111.1.el10_0 +28
    • Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) kernel-tools-libs-devel-6.12.0-55.111.1.el10_0, libperf-6.12.0-55.111.1.el10_0
    • Red Hat Enterprise Linux Real Time EUS (v. 10.0) kernel-rt-6.12.0-55.111.1.el10_0, kernel-rt-64k-6.12.0-55.111.1.el10_0, kernel-rt-64k-core-6.12.0-55.111.1.el10_0 +21
    • Red Hat Enterprise Linux Real Time for NFV EUS (v. 10.0) kernel-rt-6.12.0-55.111.1.el10_0, kernel-rt-core-6.12.0-55.111.1.el10_0, kernel-rt-debug-6.12.0-55.111.1.el10_0 +11
  • RHSA-2026:76739 Released 2026-10-08 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-687.55.1.el9_8, kernel-64k-debug-devel-matched-5.14.0-687.55.1.el9_8, kernel-64k-devel-5.14.0-687.55.1.el9_8 +12
    • Red Hat Enterprise Linux BaseOS (v. 9) kernel-5.14.0-687.55.1.el9_8, kernel-64k-5.14.0-687.55.1.el9_8, kernel-64k-core-5.14.0-687.55.1.el9_8 +28
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) kernel-tools-libs-devel-5.14.0-687.55.1.el9_8, libperf-5.14.0-687.55.1.el9_8
    • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt-5.14.0-687.55.1.el9_8, kernel-rt-64k-5.14.0-687.55.1.el9_8, kernel-rt-64k-core-5.14.0-687.55.1.el9_8 +21
    • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt-5.14.0-687.55.1.el9_8, kernel-rt-core-5.14.0-687.55.1.el9_8, kernel-rt-debug-5.14.0-687.55.1.el9_8 +9
  • RHSA-2026:64775 Released 2026-09-08 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream (v. 10) kernel-64k-debug-devel-6.12.0-211.52.1.el10_2, kernel-64k-debug-devel-matched-6.12.0-211.52.1.el10_2, kernel-64k-devel-6.12.0-211.52.1.el10_2 +12
    • Red Hat Enterprise Linux BaseOS (v. 10) kernel-6.12.0-211.52.1.el10_2, kernel-64k-6.12.0-211.52.1.el10_2, kernel-64k-core-6.12.0-211.52.1.el10_2 +29
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) kernel-tools-libs-devel-6.12.0-211.52.1.el10_2, libperf-6.12.0-211.52.1.el10_2
    • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt-6.12.0-211.52.1.el10_2, kernel-rt-64k-6.12.0-211.52.1.el10_2, kernel-rt-64k-core-6.12.0-211.52.1.el10_2 +21
    • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt-6.12.0-211.52.1.el10_2, kernel-rt-core-6.12.0-211.52.1.el10_2, kernel-rt-debug-6.12.0-211.52.1.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 9AffectedNo fix yet
Red Hat CodeReady Linux Builder EUS (v.9.6)Fixed RHSA-2026:91492
Red Hat Enterprise Linux AppStream (v. 10)Fixed RHSA-2026:64775
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2026:76739
Red Hat Enterprise Linux AppStream E4S (v.9.2)Fixed RHSA-2026:92993
Red Hat Enterprise Linux AppStream E4S (v.9.4)Fixed RHSA-2026:91489
Red Hat Enterprise Linux AppStream EUS (v. 10.0)Fixed RHSA-2026:83707
Red Hat Enterprise Linux AppStream EUS (v.9.6)Fixed RHSA-2026:91492
Red Hat Enterprise Linux BaseOS (v. 10)Fixed RHSA-2026:64775
Red Hat Enterprise Linux BaseOS (v. 9)Fixed RHSA-2026:76739
Red Hat Enterprise Linux BaseOS E4S (v.9.2)Fixed RHSA-2026:92993
Red Hat Enterprise Linux BaseOS E4S (v.9.4)Fixed RHSA-2026:91489
Red Hat Enterprise Linux BaseOS EUS (v. 10.0)Fixed RHSA-2026:83707
Red Hat Enterprise Linux BaseOS EUS (v.9.6)Fixed RHSA-2026:91492
Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)Fixed RHSA-2026:64775
Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)Fixed RHSA-2026:76739
Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0)Fixed RHSA-2026:83707
Red Hat Enterprise Linux Real Time (v. 10)Fixed RHSA-2026:64775
Red Hat Enterprise Linux Real Time (v. 9)Fixed RHSA-2026:76739
Red Hat Enterprise Linux Real Time E4S (v.9.2)Fixed RHSA-2026:93047
Red Hat Enterprise Linux Real Time E4S (v.9.4)Fixed RHSA-2026:91489
Red Hat Enterprise Linux Real Time EUS (v. 10.0)Fixed RHSA-2026:83707
Red Hat Enterprise Linux Real Time EUS (v.9.6)Fixed RHSA-2026:91492
Red Hat Enterprise Linux Real Time for NFV (v. 10)Fixed RHSA-2026:64775
Red Hat Enterprise Linux Real Time for NFV (v. 9)Fixed RHSA-2026:76739
Red Hat Enterprise Linux Real Time for NFV E4S (v.9.2)Fixed RHSA-2026:93047
Red Hat Enterprise Linux Real Time for NFV E4S (v.9.4)Fixed RHSA-2026:91489
Red Hat Enterprise Linux Real Time for NFV EUS (v. 10.0)Fixed RHSA-2026:83707
Red Hat Enterprise Linux Real Time for NFV EUS (v.9.6)Fixed RHSA-2026:91492
Not affected: 3 products
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 7
  • Red Hat Enterprise Linux 8

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-63993
  2. 2026-10-03 Alias added: GHSA-p6vc-4hvx-xvcw
  3. 2026-10-09 Fix available: RHSA-2026:76739 · Red Hat
  4. 2026-10-09 Fix available: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux BaseOS (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) +2 · Red Hat
  5. 2026-10-13 Affected versions changed · Red Hat
  6. 2026-10-16 CISA SSVC decision points changed
  7. 2026-10-18 Fix available: RHSA-2026:83707 · Red Hat
  8. 2026-10-18 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
  9. 2026-10-19 Weakness changed · CISA ADP
  10. 2026-10-29 Fix available: Red Hat Enterprise Linux AppStream E4S (v.9.4), Red Hat Enterprise Linux BaseOS E4S (v.9.4), Red Hat Enterprise Linux Real Time E4S (v.9.4) +1 · Red Hat
  11. 2026-10-29 Fix available: RHSA-2026:91489 · Red Hat
  12. 2026-10-30 Fix available: RHSA-2026:91492 · Red Hat
  13. 2026-10-30 Fix available: Red Hat CodeReady Linux Builder EUS (v.9.6), Red Hat Enterprise Linux AppStream EUS (v.9.6), Red Hat Enterprise Linux BaseOS EUS (v.9.6) +2 · Red Hat
  14. 2026-10-30 Fix available: RHSA-2026:93047 · Red Hat
  15. 2026-10-30 Fix available: Red Hat Enterprise Linux AppStream E4S (v.9.2), Red Hat Enterprise Linux BaseOS E4S (v.9.2), Red Hat Enterprise Linux Real Time E4S (v.9.2) +1 · Red Hat
  16. 2026-10-31 Fix available: RHSA-2026:92993 · Red Hat

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