CVE-2026-72392: Linux Vulnerability

Description

In the Linux kernel, the following vulnerability has been resolved: ipv6: fib6: fix NULL deref in fib6_walk_continue() on multi-batch dump inet6_dump_fib() saves its progress in cb->args[1] as a positional index within the current hash chain. Between batches, a concurrent fib6_new_table() can insert a new table at the chain head, shifting all existing entries. The saved index then lands on a different table, causing fib6_dump_table() to set w->root to the wrong table while w->node still points into the previous one. fib6_walk_continue() dereferences w->node->parent (NULL) and panics: BUG: kernel NULL pointer dereference, address: 0000000000000008 RIP: 0010:fib6_walk_continue+0x6e/0x170 Call Trace: <TASK> fib6_dump_table.isra.0+0xc5/0x240 inet6_dump_fib+0xf6/0x420 rtnl_dumpit+0x30/0xa0 netlink_dump+0x15b/0x460 netlink_recvmsg+0x1d6/0x2a0 ____sys_recvmsg+0x17a/0x190 Fix by storing tb->tb6_id in cb->args[1] instead of a positional index. On resume, skip entries until the id matches; a concurrent head-insert can never match the saved id, so the walker always resumes on the correct table.

Metrics

EPSS Probability

0.21%

11.0th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

Vendor	Product	Versions
Linux	Linux	>= 1b43af5480c351dbcb2eef478bafe179cbeb6e83, < ee73a32dd258d4af66831ff006b771e19812b322; >= 1b43af5480c351dbcb2eef478bafe179cbeb6e83, < 89f9c5fee3c64c5cabc34e65599308fd3c879cf9; >= 1b43af5480c351dbcb2eef478bafe179cbeb6e83, < cb90a774a9c6c46961a44949a246fbb61f5f934c; >= 1b43af5480c351dbcb2eef478bafe179cbeb6e83, < 27210d433a8c5fe6bf7278a04bbaeb49a81d0290; >= 1b43af5480c351dbcb2eef478bafe179cbeb6e83, < 059efb48dd746518898faaa9b965511009b59639; >= 1b43af5480c351dbcb2eef478bafe179cbeb6e83, < d8a01d27873e04bebd357dc87859aa756e0b28b2; >= 1b43af5480c351dbcb2eef478bafe179cbeb6e83, < 110ccbd28c9444866fcc84ba96a2ad64fa6e95ae; >= 1b43af5480c351dbcb2eef478bafe179cbeb6e83, < 9facb861dc6b9b9ea9793ef5032a9a826f7a4229
Linux	Linux	2.6.19

References

Timeline

Published: Aug 15, 2026
Last Modified: Aug 19, 2026
Status: Received

Frequently Asked Questions

What is CVE-2026-72392?

In the Linux kernel, the following vulnerability has been resolved: ipv6: fib6: fix NULL deref in fib6_walk_continue() on multi-batch dump inet6_dump_fib() saves its progress in cb->args[1] as a positional index within the current hash chain. Between batches, a concurrent fib6_new_table() can insert a new table at the chain head, shifting all existing entries. The saved index then lands on a different table, causing fib6_dump_table() to set w->root to the wrong table while w->node still points into the previous one. fib6_walk_continue() dereferences w->node->parent (NULL) and panics: BUG: kernel NULL pointer dereference, address: 0000000000000008 RIP: 0010:fib6_walk_continue+0x6e/0x170 Call Trace: <TASK> fib6_dump_table.isra.0+0xc5/0x240 inet6_dump_fib+0xf6/0x420 rtnl_dumpit+0x30/0xa0 netlink_dump+0x15b/0x460 netlink_recvmsg+0x1d6/0x2a0 ____sys_recvmsg+0x17a/0x190 Fix by storing tb->tb6_id in cb->args[1] instead of a positional index. On resume, skip entries until the id matches; a concurrent head-insert can never match the saved id, so the walker always resumes on the correct table.

How severe is CVE-2026-72392?

Severity scoring for CVE-2026-72392 is pending analysis. The EPSS model estimates a 0.21% probability of exploitation in the next 30 days.

How do I fix CVE-2026-72392?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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