CVE-2026-100071 — net: hsr: free learned nodes on device setup failure
In the Linux kernel, the following vulnerability has been resolved: net: hsr: free learned nodes on device setup failure hsr_dev_finalize() can fail after a lower-device RX handler has already been registered (slave A is added before the failable slave B and interlink adds). RX handlers run in softirq regardless of the master's state, so frames received in that window can learn dynamic nodes into node_db, and the error unwind never releases them. Free both owned dynamic databases in the unwind, mirroring hsr_dellink(). proxy_node_db is provably empty on every current error exit (only interlink RX feeds it, and the interlink add is the last failable step) and is freed for symmetry. The order is safe: hsr_del_port() unregisters each RX handler with synchronize_net() before hsr_del_nodes() runs, which removes remaining entries with list_del_rcu() and defers their release with call_rcu() for readers already under RCU.
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 | ≥ 81ba6afd6e6443d2bf4bf40f16df1f1f91c603f8 and < e691eee886871b933d772ffc76d66c80b4c0a25e≥ 81ba6afd6e6443d2bf4bf40f16df1f1f91c603f8 and < 0a340ffd96943a49a78e367efac9517ca767d99b≥ 81ba6afd6e6443d2bf4bf40f16df1f1f91c603f8 and < f7289e3492f2694dccd3d79287e0e31879b58650≥ 81ba6afd6e6443d2bf4bf40f16df1f1f91c603f8 and < 65702339b3e9fd792f65d4b740928798194d86ce≥ 81ba6afd6e6443d2bf4bf40f16df1f1f91c603f8 and < 49b01f2939abc676a6f9a118f07a10110ee5f683≥ 81ba6afd6e6443d2bf4bf40f16df1f1f91c603f8 and < 7f16289b91eb316f170a6bd22d32e6c632f6a5b6version 3.17 | Vulnerable | CVE Program (cve.org) e CISA ADP |
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 · → Undergoing Analysis
- 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
6 on the record
- git.kernel.org/stable/c/65702339b3e9fd792f65d4b740928798194d86ce
- git.kernel.org/stable/c/e691eee886871b933d772ffc76d66c80b4c0a25e
- git.kernel.org/stable/c/0a340ffd96943a49a78e367efac9517ca767d99b
- git.kernel.org/stable/c/49b01f2939abc676a6f9a118f07a10110ee5f683
- git.kernel.org/stable/c/f7289e3492f2694dccd3d79287e0e31879b58650
- git.kernel.org/stable/c/7f16289b91eb316f170a6bd22d32e6c632f6a5b6
Elsewhere on this site
Related CVEs (same products)
- Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 1d
- Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 1d
- Unknown CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 2d
- Unknown CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 2d
- Unknown CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 2d
- Unknown CVE-2026-98427 net/sched: codel: bound the dropping loop per dequeue call 2d
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-2026-100071 is "net: hsr: free learned nodes on device setup failure", 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 0.16% 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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