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TI-2026-24241 Aliases CVE-2026-31684GHSA-gj33-f2q3-mjhg

net: sched: act_csum: validate nested VLAN headers

Priority LOW 24Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
None · None · High
Fix status
Partial Red Hat: 41 fixed, 1 without a fix

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat.

Summary

In the Linux kernel, the following vulnerability has been resolved: net: sched: act_csum: validate nested VLAN headers tcf_csum_act() walks nested VLAN headers directly from skb->data when an skb still carries in-payload VLAN tags. The current code reads vlan->h_vlan_encapsulated_proto and then pulls VLAN_HLEN bytes without first ensuring that the full VLAN header is present in the linear area. If only part of an inner VLAN header is linearized, accessing h_vlan_encapsulated_proto reads past the linear area, and the following skb_pull(VLAN_HLEN) may violate skb invariants. Fix this by requiring pskb_may_pull(skb, VLAN_HLEN) before accessing and pulling each nested VLAN header. If the header still is not fully available, drop the packet through the existing error path.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00117 1st percentileScored 2026-11-07
Fix Partial Linux (Linux): 4.20, 5.10.258, 5.15.209 +6Red Hat: 14 advisoriesRed Hat: 41 fixed, 1 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

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

Affected products

VendorProductAffected versionsFixed inStatusSource
LinuxLinux4.19.99 to before 4.204.20Patch availableCNA
LinuxLinux5.1 and later5.10.258, 5.15.209, 6.1.175, 6.6.136, 6.12.83, 6.18.24, 6.19.14, 7.0Patch availableCNA
  • Linux VendorLinux Affected 4.19.99 to before 4.20 Fixed in 4.20 Patch available CNA
  • Linux VendorLinux Affected 5.1 and later Fixed in 5.10.258, 5.15.209, 6.1.175, 6.6.136, 6.12.83, 6.18.24, 6.19.14, 7.0 Patch available CNA

CPE configurations NVD · 8

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*4.19.99 to before 4.20; 5.1 to before 6.6.136; 6.7 to before 6.12.83; 6.13 to before 6.18.24; 6.19 to before 6.19.14VulnerableLinux
cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*7.0 rc1VulnerableLinux
cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*7.0 rc2VulnerableLinux
cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*7.0 rc3VulnerableLinux
cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*7.0 rc4VulnerableLinux
cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*7.0 rc5VulnerableLinux
cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:*7.0 rc6VulnerableLinux
cpe:2.3:o:linux:linux_kernel:7.0:rc7:*:*:*:*:*:*7.0 rc7VulnerableLinux
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 4.19.99 to before 4.20; 5.1 to before 6.6.136; 6.7 to before 6.12.83; 6.13 to before 6.18.24; 6.19 to before 6.19.14 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:* Versions 7.0 rc1 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:* Versions 7.0 rc2 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:* Versions 7.0 rc3 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:* Versions 7.0 rc4 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:* Versions 7.0 rc5 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:* Versions 7.0 rc6 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:7.0:rc7:*:*:*:*:*:* Versions 7.0 rc7 Vulnerable ·Linux

Remediation

  • Fix · CNA Linux (Linux) Fixed in 4.20
  • Fix · CNA Linux (Linux) Fixed in 5.10.258, 5.15.209, 6.1.175, 6.6.136, 6.12.83, 6.18.24, 6.19.14, 7.0

Red Hat 14 advisories

  • RHSA-2026:47632 Released 2026-07-30 · Red Hat rating Important
    kernel-rt security, bug fix, and enhancement update
    • Red Hat Enterprise Linux Real Time E4S (v.9.2) kernel-rt-5.14.0-284.183.1.rt14.468.el9_2, kernel-rt-core-5.14.0-284.183.1.rt14.468.el9_2, kernel-rt-debug-5.14.0-284.183.1.rt14.468.el9_2 +9
    • Red Hat Enterprise Linux Real Time for NFV E4S (v.9.2) kernel-rt-5.14.0-284.183.1.rt14.468.el9_2, kernel-rt-core-5.14.0-284.183.1.rt14.468.el9_2, kernel-rt-debug-5.14.0-284.183.1.rt14.468.el9_2 +11
  • RHSA-2026:47633 Released 2026-07-30 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat Enterprise Linux BaseOS AUS (v.8.4) bpftool-4.18.0-305.199.1.el8_4, kernel-4.18.0-305.199.1.el8_4, kernel-abi-stablelists-4.18.0-305.199.1.el8_4 +14
    • Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.4) bpftool-4.18.0-305.199.1.el8_4, kernel-4.18.0-305.199.1.el8_4, kernel-abi-stablelists-4.18.0-305.199.1.el8_4 +14
  • RHSA-2026:47739 Released 2026-07-29 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream E4S (v.9.2) kernel-64k-debug-devel-5.14.0-284.183.1.el9_2, kernel-64k-debug-devel-matched-5.14.0-284.183.1.el9_2, kernel-64k-devel-5.14.0-284.183.1.el9_2 +10
    • Red Hat Enterprise Linux BaseOS E4S (v.9.2) bpftool-7.0.0-284.183.1.el9_2, kernel-5.14.0-284.183.1.el9_2, kernel-64k-5.14.0-284.183.1.el9_2 +29
Show 11 more Red Hat advisories
  • RHSA-2026:47869 Released 2026-07-29 · Red Hat rating Important
    kernel security update
    • Red Hat Enterprise Linux BaseOS E4S (v.8.8) bpftool-4.18.0-477.156.1.el8_8, kernel-4.18.0-477.156.1.el8_8, kernel-abi-stablelists-4.18.0-477.156.1.el8_8 +14
    • Red Hat Enterprise Linux BaseOS TUS (v.8.8) bpftool-4.18.0-477.156.1.el8_8, kernel-4.18.0-477.156.1.el8_8, kernel-abi-stablelists-4.18.0-477.156.1.el8_8 +14
  • RHSA-2026:44694 Released 2026-07-23 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream EUS (v. 10.0) kernel-64k-debug-devel-6.12.0-55.92.1.el10_0, kernel-64k-debug-devel-matched-6.12.0-55.92.1.el10_0, kernel-64k-devel-6.12.0-55.92.1.el10_0 +12
    • Red Hat Enterprise Linux BaseOS EUS (v. 10.0) kernel-6.12.0-55.92.1.el10_0, kernel-64k-6.12.0-55.92.1.el10_0, kernel-64k-core-6.12.0-55.92.1.el10_0 +28
    • Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) kernel-tools-libs-devel-6.12.0-55.92.1.el10_0, libperf-6.12.0-55.92.1.el10_0
    • Red Hat Enterprise Linux Real Time EUS (v. 10.0) kernel-rt-6.12.0-55.92.1.el10_0, kernel-rt-64k-6.12.0-55.92.1.el10_0, kernel-rt-64k-core-6.12.0-55.92.1.el10_0 +21
    • Red Hat Enterprise Linux Real Time for NFV EUS (v. 10.0) kernel-rt-6.12.0-55.92.1.el10_0, kernel-rt-core-6.12.0-55.92.1.el10_0, kernel-rt-debug-6.12.0-55.92.1.el10_0 +11
  • RHSA-2026:44385 Released 2026-07-23 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat CodeReady Linux Builder EUS (v.9.6) kernel-tools-libs-devel-5.14.0-570.129.1.el9_6, libperf-5.14.0-570.129.1.el9_6
    • Red Hat Enterprise Linux AppStream EUS (v.9.6) kernel-64k-debug-devel-5.14.0-570.129.1.el9_6, kernel-64k-debug-devel-matched-5.14.0-570.129.1.el9_6, kernel-64k-devel-5.14.0-570.129.1.el9_6 +12
    • Red Hat Enterprise Linux BaseOS EUS (v.9.6) kernel-5.14.0-570.129.1.el9_6, kernel-64k-5.14.0-570.129.1.el9_6, kernel-64k-core-5.14.0-570.129.1.el9_6 +28
    • Red Hat Enterprise Linux Real Time EUS (v.9.6) kernel-rt-5.14.0-570.129.1.el9_6, kernel-rt-64k-5.14.0-570.129.1.el9_6, kernel-rt-64k-core-5.14.0-570.129.1.el9_6 +21
    • Red Hat Enterprise Linux Real Time for NFV EUS (v.9.6) kernel-rt-5.14.0-570.129.1.el9_6, kernel-rt-core-5.14.0-570.129.1.el9_6, kernel-rt-debug-5.14.0-570.129.1.el9_6 +11
  • RHSA-2026:43231 Released 2026-07-22 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream E4S (v.9.4) kernel-64k-debug-devel-5.14.0-427.139.1.el9_4, kernel-64k-debug-devel-matched-5.14.0-427.139.1.el9_4, kernel-64k-devel-5.14.0-427.139.1.el9_4 +11
    • Red Hat Enterprise Linux BaseOS E4S (v.9.4) bpftool-7.3.0-427.139.1.el9_4, kernel-5.14.0-427.139.1.el9_4, kernel-64k-5.14.0-427.139.1.el9_4 +29
    • Red Hat Enterprise Linux Real Time E4S (v.9.4) kernel-rt-5.14.0-427.139.1.el9_4, kernel-rt-core-5.14.0-427.139.1.el9_4, kernel-rt-debug-5.14.0-427.139.1.el9_4 +9
    • Red Hat Enterprise Linux Real Time for NFV E4S (v.9.4) kernel-rt-5.14.0-427.139.1.el9_4, kernel-rt-core-5.14.0-427.139.1.el9_4, kernel-rt-debug-5.14.0-427.139.1.el9_4 +11
  • RHSA-2026:41235 Released 2026-07-17 · Red Hat rating Important
    kernel security update
    • Red Hat Enterprise Linux Server (v. 7 ELS) bpftool-3.10.0-1160.156.1.el7, kernel-3.10.0-1160.156.1.el7, kernel-abi-whitelists-3.10.0-1160.156.1.el7 +11
    • Red Hat Enterprise Linux Server Optional (v. 7 ELS) kernel-debug-devel-3.10.0-1160.156.1.el7, kernel-tools-libs-devel-3.10.0-1160.156.1.el7
  • RHSA-2026:41234 Released 2026-07-17 · Red Hat rating Important
    kernel-rt security update
    • Red Hat Enterprise Linux for Real Time (v. 7 ELS) kernel-rt-3.10.0-1160.156.1.rt56.1308.el7, kernel-rt-debug-3.10.0-1160.156.1.rt56.1308.el7, kernel-rt-debug-devel-3.10.0-1160.156.1.rt56.1308.el7 +4
  • RHSA-2026:40068 Released 2026-07-15 · Red Hat rating Important
    kernel security update
    • Red Hat Enterprise Linux BaseOS AUS (v.8.6) bpftool-4.18.0-372.201.1.el8_6, kernel-4.18.0-372.201.1.el8_6, kernel-abi-stablelists-4.18.0-372.201.1.el8_6 +14
    • Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6) bpftool-4.18.0-372.201.1.el8_6, kernel-4.18.0-372.201.1.el8_6, kernel-abi-stablelists-4.18.0-372.201.1.el8_6 +14
  • RHSA-2026:21745 Released 2026-05-28 · Red Hat rating Important
    kernel-rt security update
    • Red Hat Enterprise Linux NFV (v. 8) kernel-rt-4.18.0-553.126.1.rt7.467.el8_10, kernel-rt-core-4.18.0-553.126.1.rt7.467.el8_10, kernel-rt-debug-4.18.0-553.126.1.rt7.467.el8_10 +9
    • Red Hat Enterprise Linux RT (v. 8) kernel-rt-4.18.0-553.126.1.rt7.467.el8_10, kernel-rt-core-4.18.0-553.126.1.rt7.467.el8_10, kernel-rt-debug-4.18.0-553.126.1.rt7.467.el8_10 +7
  • RHSA-2026:21706 Released 2026-05-28 · Red Hat rating Important
    kernel security update
    • Red Hat Enterprise Linux BaseOS (v. 8) bpftool-4.18.0-553.126.1.el8_10, kernel-4.18.0-553.126.1.el8_10, kernel-abi-stablelists-4.18.0-553.126.1.el8_10 +19
    • Red Hat Enterprise Linux CRB (v. 8) kernel-tools-libs-devel-4.18.0-553.126.1.el8_10
  • RHSA-2026:21556 Released 2026-05-28 · Red Hat rating Important
    kernel security update
    • Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-687.12.1.el9_8, kernel-64k-debug-devel-matched-5.14.0-687.12.1.el9_8, kernel-64k-devel-5.14.0-687.12.1.el9_8 +12
    • Red Hat Enterprise Linux BaseOS (v. 9) kernel-5.14.0-687.12.1.el9_8, kernel-64k-5.14.0-687.12.1.el9_8, kernel-64k-core-5.14.0-687.12.1.el9_8 +28
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) kernel-tools-libs-devel-5.14.0-687.12.1.el9_8, libperf-5.14.0-687.12.1.el9_8
    • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt-5.14.0-687.12.1.el9_8, kernel-rt-64k-5.14.0-687.12.1.el9_8, kernel-rt-64k-core-5.14.0-687.12.1.el9_8 +21
    • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt-5.14.0-687.12.1.el9_8, kernel-rt-core-5.14.0-687.12.1.el9_8, kernel-rt-debug-5.14.0-687.12.1.el9_8 +9
  • RHSA-2026:21557 Released 2026-05-28 · Red Hat rating Important
    kernel security update
    • Red Hat Enterprise Linux AppStream (v. 10) kernel-64k-debug-devel-6.12.0-211.18.1.el10_2, kernel-64k-debug-devel-matched-6.12.0-211.18.1.el10_2, kernel-64k-devel-6.12.0-211.18.1.el10_2 +12
    • Red Hat Enterprise Linux BaseOS (v. 10) kernel-6.12.0-211.18.1.el10_2, kernel-64k-6.12.0-211.18.1.el10_2, kernel-64k-core-6.12.0-211.18.1.el10_2 +29
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) kernel-tools-libs-devel-6.12.0-211.18.1.el10_2, libperf-6.12.0-211.18.1.el10_2
    • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt-6.12.0-211.18.1.el10_2, kernel-rt-64k-6.12.0-211.18.1.el10_2, kernel-rt-64k-core-6.12.0-211.18.1.el10_2 +21
    • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt-6.12.0-211.18.1.el10_2, kernel-rt-core-6.12.0-211.18.1.el10_2, kernel-rt-debug-6.12.0-211.18.1.el10_2 +9

Vendor assessments

Red Hat

Red Hat rating: Moderate. 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-2026:44385
Red Hat Enterprise Linux AppStream (v. 10)Fixed RHSA-2026:21557
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2026:21556
Red Hat Enterprise Linux AppStream E4S (v.9.2)Fixed RHSA-2026:47739
Red Hat Enterprise Linux AppStream E4S (v.9.4)Fixed RHSA-2026:43231
Red Hat Enterprise Linux AppStream EUS (v. 10.0)Fixed RHSA-2026:44694
Red Hat Enterprise Linux AppStream EUS (v.9.6)Fixed RHSA-2026:44385
Red Hat Enterprise Linux BaseOS (v. 10)Fixed RHSA-2026:21557
Red Hat Enterprise Linux BaseOS (v. 8)Fixed RHSA-2026:21706
Red Hat Enterprise Linux BaseOS (v. 9)Fixed RHSA-2026:21556
Red Hat Enterprise Linux BaseOS AUS (v.8.4)Fixed RHSA-2026:47633
Red Hat Enterprise Linux BaseOS AUS (v.8.6)Fixed RHSA-2026:40068
Red Hat Enterprise Linux BaseOS E4S (v.8.8)Fixed RHSA-2026:47869
Red Hat Enterprise Linux BaseOS E4S (v.9.2)Fixed RHSA-2026:47739
Red Hat Enterprise Linux BaseOS E4S (v.9.4)Fixed RHSA-2026:43231
Red Hat Enterprise Linux BaseOS EUS (v. 10.0)Fixed RHSA-2026:44694
Red Hat Enterprise Linux BaseOS EUS (v.9.6)Fixed RHSA-2026:44385
Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.4)Fixed RHSA-2026:47633
Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6)Fixed RHSA-2026:40068
Red Hat Enterprise Linux BaseOS TUS (v.8.8)Fixed RHSA-2026:47869
Red Hat Enterprise Linux CRB (v. 8)Fixed RHSA-2026:21706
Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)Fixed RHSA-2026:21557
Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)Fixed RHSA-2026:21556
Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0)Fixed RHSA-2026:44694
Red Hat Enterprise Linux NFV (v. 8)Fixed RHSA-2026:21745
Red Hat Enterprise Linux RT (v. 8)Fixed RHSA-2026:21745
Red Hat Enterprise Linux Real Time (v. 10)Fixed RHSA-2026:21557
Red Hat Enterprise Linux Real Time (v. 9)Fixed RHSA-2026:21556
Red Hat Enterprise Linux Real Time E4S (v.9.2)Fixed RHSA-2026:47632
Red Hat Enterprise Linux Real Time E4S (v.9.4)Fixed RHSA-2026:43231
Red Hat Enterprise Linux Real Time EUS (v. 10.0)Fixed RHSA-2026:44694
Red Hat Enterprise Linux Real Time EUS (v.9.6)Fixed RHSA-2026:44385
Red Hat Enterprise Linux Real Time for NFV (v. 10)Fixed RHSA-2026:21557
Red Hat Enterprise Linux Real Time for NFV (v. 9)Fixed RHSA-2026:21556
Red Hat Enterprise Linux Real Time for NFV E4S (v.9.2)Fixed RHSA-2026:47632
Red Hat Enterprise Linux Real Time for NFV E4S (v.9.4)Fixed RHSA-2026:43231
Red Hat Enterprise Linux Real Time for NFV EUS (v. 10.0)Fixed RHSA-2026:44694
Red Hat Enterprise Linux Real Time for NFV EUS (v.9.6)Fixed RHSA-2026:44385
Red Hat Enterprise Linux Server (v. 7 ELS)Fixed RHSA-2026:41235
Red Hat Enterprise Linux Server Optional (v. 7 ELS)Fixed RHSA-2026:41235
Red Hat Enterprise Linux for Real Time (v. 7 ELS)Fixed RHSA-2026:41234
Not affected: 1 product
  • Red Hat Enterprise Linux 6

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-31684
  2. 2026-10-03 Alias added: GHSA-gj33-f2q3-mjhg
  3. 2026-11-06 CISA SSVC decision points changed

References

Patch 5

Other 3

  • 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