TI-2026-50337 Aliases CVE-2026-72057 GHSA-r6mf-v83v-v392

net/sched: act_ct: preserve tc_skb_cb across defragmentation

MEDIUM 42CWE-662Published 2026-08-15 · Updated 2026-10-19

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: —
Confidentiality · integrity · availability: None · Low · High
Fix status: Partial Red Hat: 3 without a fix

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

Summary

In the Linux kernel, the following vulnerability has been resolved: net/sched: act_ct: preserve tc_skb_cb across defragmentation tcf_ct_handle_fragments() calls nf_ct_handle_fragments() without saving and restoring skb->cb. The defrag helper clears IPCB/IP6CB, which aliases the tc_skb_cb/qdisc_skb_cb control buffer. Fragmented traffic through act_ct therefore loses qdisc metadata such as pkt_segs and can trigger WARN_ON_ONCE() in qdisc_pkt_segs() when panic_on_warn is enabled. Save and restore the full tc_skb_cb around nf_ct_handle_fragments(), matching the pattern used by ovs_ct_handle_fragments().

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00585 48th percentileScored 2026-11-07

Fix Partial Linux (Linux): 5.15.217, 6.1.184, 6.6.145 +4Red Hat: 3 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: Yes
Technical impact: Partial

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

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
Linux	Linux	5.15.13 to before 5.15.217	5.15.217	Patch available	CNA
Linux	Linux	5.16 and later	5.15.217, 6.1.184, 6.6.145, 6.12.97, 6.18.40, 7.1.5, 7.2	Patch available	CNA

Linux VendorLinux Affected 5.15.13 to before 5.15.217 Fixed in 5.15.217 Patch available CNA
Linux VendorLinux Affected 5.16 and later Fixed in 5.15.217, 6.1.184, 6.6.145, 6.12.97, 6.18.40, 7.1.5, 7.2 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPE	Versions	Role	Vendor
cpe:2.3:o:linux:linux_kernel::::::::	—	—	Linux

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions — — ·Linux

Remediation

Fix · CNA Linux (Linux) Fixed in 5.15.217
Fix · CNA Linux (Linux) Fixed in 5.15.217, 6.1.184, 6.6.145, 6.12.97, 6.18.40, 7.1.5, 7.2

Vendor assessments

Red Hat

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

Product	Status	Plan or fix
Red Hat Enterprise Linux 10	Affected	No fix yet: Fix deferred
Red Hat Enterprise Linux 8	Affected	No fix yet
Red Hat Enterprise Linux 9	Affected	No fix yet

Not affected: 2 products

Red Hat Enterprise Linux 6
Red Hat Enterprise Linux 7

Timeline

2026-10-02 Threatist record created from CVE-2026-72057
2026-10-03 Alias added: GHSA-r6mf-v83v-v392
2026-10-16 CISA SSVC decision points changed
2026-10-16 Priority changed: LOW → MEDIUM
2026-10-20 Weakness changed · CISA ADP
2026-11-06 Affected versions changed · Red Hat
2026-11-06 CVSS score changed · Red Hat

References

Other 7

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-2021-02452 Incorrect authorization in Ubuntu linux kernel 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

See all 21727 →

Sources

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