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CVE.org (no NVD analysis yet)· CNA Linux

CVE-2026-99201: netlink: avoid hashing the network namespace pointer

Noroxi assessment

Priority: Monitor (action score 0/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.17% (FIRST EPSS).
  • Fixed version: Linux Linux 078deff25f8a849ecd1c3fe17b1e473b1cf44f28, 18edcb9945118beb7a1b64a31a7370ecab485a79, 41a2f69f091b0765f17890d8ac04852c12f25cf6; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 Release Notes; azl3 kernel 6.6.159.1-1 on Azure Linux 3.0 Release Notes.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 078deff25f8a849ecd1c3fe17b1e473b1cf44f28, 18edcb9945118beb7a1b64a31a7370ecab485a79, 41a2f69f091b0765f17890d8ac04852c12f25cf6; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 Release Notes; azl3 kernel 6.6.159.1-1 on Azure Linux 3.0 Release Notes or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: netlink: avoid hashing the network namespace pointer The netlink rhashtable key includes a raw struct net pointer and a user-controlled port ID. Both /proc/net/netlink and socket diagnostics expose the table's bucket order. By binding and rebinding chosen NETLINK_USERSOCK port IDs, an unprivileged reader can distinguish equal buckets and recover the low bits of the Jenkins hash. Its 32-bit seed and the limited set of kernel-image slides can then be searched offline to recover the address of init_net. Use the namespace's unique, non-address net_cookie in the comparison key instead. It is assigned before the per-net initializers run and remains unchanged for the namespace's lifetime. The lookup key and object hash are still built by netlink_compare_arg_init(), keeping lookup, insertion, removal and rehashing consistent while preserving namespace separation. Neither public table walker needs to change. Reading the socket's namespace cookie in netlink_compare() is safe under RCU, including during namespace teardown. netlink_release() removes the socket from the hash table and defers its final put with call_rcu(). cleanup_net() runs the per-net exit methods and waits for outstanding RCU callbacks with rcu_barrier() before freeing namespace storage. Unlike ns.ns_id, net_cookie is also available and initialized during setup_net() in older stable kernels, making the change straightforward to backport to v5.15 and later.

—No exploit Fix available
Published
Oct 28, 2026
Updated
Oct 30, 2026
EPSS
0.1% · 6th percentile
CWE
—

Report tools

JSON

Action score

0

Monitor

Low priority for now.

CVSS
0 / 40 · —
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

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  • Not in KEV: no record of exploitation in the wild
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  • A fix has been released

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Noroxi analysis

What does it mean in your environment?

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 4.1affected
    • c428ecd1a21f1457ca3beb4df71b8a079c410e41 and later · before c61431f3b8c9824e9848a0308054f92b27fa7794affected · git
    • c428ecd1a21f1457ca3beb4df71b8a079c410e41 and later · before f8d2690f3c5dfad1fc306f6d5d84a1d3176c3af9affected · git
    • c428ecd1a21f1457ca3beb4df71b8a079c410e41 and later · before c03fb9c4be3b2dd0996d91e54f65407f7f475238affected · git
    • c428ecd1a21f1457ca3beb4df71b8a079c410e41 and later · before 41a2f69f091b0765f17890d8ac04852c12f25cf6affected · git
    • c428ecd1a21f1457ca3beb4df71b8a079c410e41 and later · before 18edcb9945118beb7a1b64a31a7370ecab485a79affected · git
    • c428ecd1a21f1457ca3beb4df71b8a079c410e41 and later · before bdd55b8a8acbf6b4840ab420eb6a63774bf4593baffected · git
    • c428ecd1a21f1457ca3beb4df71b8a079c410e41 and later · before 078deff25f8a849ecd1c3fe17b1e473b1cf44f28affected · git
    • c428ecd1a21f1457ca3beb4df71b8a079c410e41 and later · before f88bb3606e4bd11ee035b682cddc2999e604609aaffected · git
    • before 4.1not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxfrom 0—
Debian:13linuxbefore 6.12.115-26.12.115-2

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
    40Plan
  • CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
    40Plan
  • CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-99199Oct 28, 2026 · net: hisilicon: hip04_eth: Move setting of netops to fix crash
    0Monitor
  • ← EarlierCVE-2026-99200Oct 28, 2026 · net: hisilicon: hisi_femac: Move setting of netops to fix crash
    0Monitor
  • Later →CVE-2026-99202Oct 28, 2026 · scsi: libsas: Fix SMP IO deadlock during HA resume
    0Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux078deff25f8a849ecd1c3fe17b1e473b1cf44f28Vendor (CNA)
Linux Linux18edcb9945118beb7a1b64a31a7370ecab485a79Vendor (CNA)
Linux Linux41a2f69f091b0765f17890d8ac04852c12f25cf6Vendor (CNA)
Linux Linuxbdd55b8a8acbf6b4840ab420eb6a63774bf4593bVendor (CNA)
Linux Linuxc03fb9c4be3b2dd0996d91e54f65407f7f475238Vendor (CNA)
Linux Linuxc61431f3b8c9824e9848a0308054f92b27fa7794Vendor (CNA)
Linux Linuxf88bb3606e4bd11ee035b682cddc2999e604609aVendor (CNA)
Linux Linuxf8d2690f3c5dfad1fc306f6d5d84a1d3176c3af9Vendor (CNA)
azl3 kernel 6.6.157.1-1 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 kernel 6.6.159.1-1 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
debian:linux6.12.115-2 · Debian:13Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. Published
  2. Fix recordedsame day
  3. TodayNov 5, 2026+8 d
EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Technical details

No CVSS vector for this record, so attack conditions can't be derived.

Weakness class (CWE)

—

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Exploit maturity— → none
  2. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (7 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records