TI-2026-50533 Aliases CVE-2026-72254 GHSA-f5p7-25h5-xxwh

netfilter: nft_fib: reject fib expression on the netdev egress hook

MEDIUM 40Published 2026-08-15 · Updated 2026-10-30

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: —
Confidentiality · integrity · availability: None · None · High
Fix status: Partial Red Hat: 2 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: netfilter: nft_fib: reject fib expression on the netdev egress hook A fib expression in a netdev egress base chain dereferences nft_in(pkt), NULL on the transmit path, causing a NULL pointer dereference at eval. nft_fib_validate() masks the hook with NF_INET_* values, but netdev hook numbers are a separate enum that aliases them (NF_NETDEV_EGRESS == NF_INET_LOCAL_IN), so an egress chain passes validation and then faults. Add nft_fib_netdev_validate() that limits each result/flag to the netdev hook where the device it reads exists: the input-device cases (OIF, OIFNAME, ADDRTYPE with F_IIF) to ingress, the output-device case (ADDRTYPE with F_OIF) to egress, ADDRTYPE with no device flag to both. Also restrict nft_fib_validate() to NFPROTO_IPV4/IPV6/INET so its NF_INET_* masks are not applied to another family's hooks.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00665 52nd percentileScored 2026-11-07

Fix Partial Linux (Linux): 6.1.191, 6.6.148, 6.12.101 +3Red Hat: 2 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	5.16 and later	6.1.191, 6.6.148, 6.12.101, 6.18.42, 7.1.5, 7.2	Patch available	CNA

Linux VendorLinux Affected 5.16 and later Fixed in 6.1.191, 6.6.148, 6.12.101, 6.18.42, 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 6.1.191, 6.6.148, 6.12.101, 6.18.42, 7.1.5, 7.2

Vendor assessments

Red Hat

Red Hat rating: Low. 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 9	Affected	No fix yet: Fix deferred

Not affected: 3 products

Red Hat Enterprise Linux 6
Red Hat Enterprise Linux 7
Red Hat Enterprise Linux 8

Timeline

2026-10-02 Threatist record created from CVE-2026-72254
2026-10-03 Alias added: GHSA-f5p7-25h5-xxwh
2026-10-16 CISA SSVC decision points changed
2026-10-16 Priority changed: LOW → MEDIUM
2026-10-30 Fix available: Linux/Linux@1258a6da042c0c283dcf5c581acb318db29c760a, Linux/[email protected] · CNA
2026-10-30 1 new reference · CNA
2026-10-31 EPSS moved to the 50th–90th percentile

References

Other 6

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 21741 →

Sources

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