CVE-2026-93226 — ipv6: use RCU iterator to dump route exceptions
In the Linux kernel, the following vulnerability has been resolved: ipv6: use RCU iterator to dump route exceptions rt6_nh_dump_exceptions() uses hlist_for_each_entry() to iterate over RCU-protected exception lists. The caller holds rcu_read_lock(), but does not hold rt6_exception_lock, so rt6_insert_exception() can concurrently add an entry with hlist_add_head_rcu(). KCSAN reports this race (irrelevant details omitted): ================================================================== BUG: KCSAN: data-race in rt6_insert_exception / rt6_nh_dump_exceptions write (marked) to 0xffff8a7c44c59620 of 8 bytes by interrupt on cpu 5: rt6_insert_exception+0x3bb/0x760 __ip6_rt_update_pmtu+0x4fe/0x750 ip6_sk_update_pmtu+0x19a/0x3b0 udpv6_err+0x3ff/0x800 icmpv6_notify+0x1e1/0x440 icmpv6_rcv+0x8c0/0xab0 ip6_protocol_deliver_rcu+0x616/0x840 ip6_input_finish+0xb9/0x160 ... entry_SYSCALL_64_after_hwframe+0x77/0x7f read to 0xffff8a7c44c59620 of 8 bytes by task 549 on cpu 14: rt6_nh_dump_exceptions+0xb3/0x260 rt6_dump_route+0x53e/0x5f0 fib6_dump_node+0x6d/0xf0 fib6_walk_continue+0x290/0x2d0 fib6_dump_table+0x28d/0x360 inet6_dump_fib+0x37d/0x620 rtnl_dumpit+0x7b/0xd0 netlink_dump+0x3ae/0x7e0 ... entry_SYSCALL_64_after_hwframe+0x77/0x7f 4 locks held by dumper/549: ... #1: (rcu_read_lock){....}-{1:3}, at: inet6_dump_fib+0x88/0x620 #2: (&tb->tb6_lock){+.-.}-{3:3}, at: fib6_dump_table+0x1e9/0x360 #3: (rcu_read_lock){....}-{1:3}, at: rt6_dump_route+0x483/0x5f0 value changed: 0xffff8a7c44e05700 -> 0xffff8a7c45d60100 Reported by Kernel Concurrency Sanitizer on: CPU: 14 UID: 0 PID: 549 Comm: dumper Not tainted 7.2.0-rc7-virtme #38 PREEMPT(lazy) ... Use hlist_for_each_entry_rcu() to safely iterate over the exception list.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.2% (30-day exploitation probability)+1
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes, errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Linux | Linux |
≥ 1e47b4837f3bdaa425727cfe09f5ae3b6c4c41a9 and < dffbfb3117138e8e0e09d05f507bd36ca1f696e5≥ 1e47b4837f3bdaa425727cfe09f5ae3b6c4c41a9 and < 6bd3f94ed858f2d072627546b4cdf712b0f8ea88≥ 1e47b4837f3bdaa425727cfe09f5ae3b6c4c41a9 and < 9c6be625e1a7258e845d6193b3b6b084a00f8e9e≥ 1e47b4837f3bdaa425727cfe09f5ae3b6c4c41a9 and < 3665abc3d2ae8a78cb67f858e848481432ec75db≥ 1e47b4837f3bdaa425727cfe09f5ae3b6c4c41a9 and < eda56ee17713f9dd834b922f7dbfa2e25fa6358c≥ 1e47b4837f3bdaa425727cfe09f5ae3b6c4c41a9 and < a602cd128d17a793e12888edc8eda85821ede7e1≥ 1e47b4837f3bdaa425727cfe09f5ae3b6c4c41a9 and < f6b1b15848fd91fe122dac0d19d3d666e35075b6≥ 1e47b4837f3bdaa425727cfe09f5ae3b6c4c41a9 and < 47cdab0d51aaa9bd85f8e4904585bd5bd4df4488 and 1 moreversion 5.3 |
Vulnerable | CVE Program (cve.org) e CISA ADP |
EPSS over time FIRST
Oct 15, 2026 → Oct 16, 2026 · 2 reading(s) · max 0.18%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Not enough vector or weakness data: use the affected application’s logs as a starting point.
Timeline
What happened to this CVE, newest first.
- 2026
- Record published
- Affected products added · linux/linux
- Source status changed · → Received
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 15, 2026 – Oct 15, 2026
References
8 on the record
- git.kernel.org/stable/c/a602cd128d17a793e12888edc8eda85821ede7e1
- git.kernel.org/stable/c/47cdab0d51aaa9bd85f8e4904585bd5bd4df4488
- git.kernel.org/stable/c/dffbfb3117138e8e0e09d05f507bd36ca1f696e5
- git.kernel.org/stable/c/3665abc3d2ae8a78cb67f858e848481432ec75db
- git.kernel.org/stable/c/eda56ee17713f9dd834b922f7dbfa2e25fa6358c
- git.kernel.org/stable/c/6bd3f94ed858f2d072627546b4cdf712b0f8ea88
- git.kernel.org/stable/c/9c6be625e1a7258e845d6193b3b6b084a00f8e9e
- git.kernel.org/stable/c/f6b1b15848fd91fe122dac0d19d3d666e35075b6
Elsewhere on this site
Related CVEs (same products)
- Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 2d
- Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 2d
- Unknown CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 3d
- Unknown CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 3d
- Unknown CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 3d
- Unknown CVE-2026-98427 net/sched: codel: bound the dropping loop per dequeue call 3d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No CVSS score published by NVD, the CNA, CISA or GitHub so far.
- No fixed version, patch or mitigation documented.
- No CISA SSVC assessment.
- No CWE classification.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-93226 is "ipv6: use RCU iterator to dump route exceptions", rated Unknown. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. EPSS 0.18% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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