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

CVE-2026-99288: inet: reject unhashed sockets during established lookups

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.
  • Fixed version: Linux Linux 8e5172cbd227fae32f3313cba1f3e1b9edb5c4fd, d69100340b4cae08d40f898f1b601032403f6be6, eb8a2d156f2c1d862fffdfd1b3432bfbcd939879.

Low priority for now. Upgrade to Linux Linux 8e5172cbd227fae32f3313cba1f3e1b9edb5c4fd, d69100340b4cae08d40f898f1b601032403f6be6, eb8a2d156f2c1d862fffdfd1b3432bfbcd939879 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

In the Linux kernel, the following vulnerability has been resolved: inet: reject unhashed sockets during established lookups TCP established ehash lookups are lockless. The socket caches involved use SLAB_TYPESAFE_BY_RCU, so memory can be reused before an RCU reader that retained its old address has finished. After a tuple match, __inet_lookup_established() and __inet6_lookup_established() acquire a reference and repeat the tuple check. They do not check whether the new object is hashed. If the address is reused for a socket with the same tuple, the lookup can acquire a reference to the new object and return it while its nulls node is unhashed. A PoC that drives reuse with a SYN cookie request socket reproduced the crash. The new request socket is unhashed and has a NULL rsk_listener. A lookup that had loaded the address of the old request socket acquired the reference published by tcp_get_cookie_sock() and returned the new object. tcp_v4_rcv() then read sk_state through the NULL listener. The resulting crash was: BUG: kernel NULL pointer dereference, address: 0000000000000012 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page ... Oops: Oops: 0000 [#1] SMP NOPTI CPU: 4 UID: 0 PID: 0 Comm: swapper/4 Not tainted 7.3.0-00591-g0e135910deec #1 PREEMPT(lazy) ... RIP: 0010:tcp_v4_rcv+0x44e/0x1280 ... R10: 0000000000000001 R11: 00000000024ca8c0 R12: 0000000000000000 ... CR2: 0000000000000012 CR3: 0000000103d50004 CR4: 0000000000770ef0 ... Call Trace: <IRQ> ? raw_local_deliver+0xae/0x240 ip_protocol_deliver_rcu+0x2d/0x180 ip_local_deliver_finish+0x84/0x100 ip_sublist_rcv_finish+0x5f/0x70 ip_sublist_rcv+0x12a/0x1d0 ip_list_rcv+0xfd/0x130 __netif_receive_skb_list_core+0x223/0x250 netif_receive_skb_list_internal+0x1d2/0x2c0 ? try_fill_recv+0x39/0x7b0 napi_complete_done+0x74/0x170 virtnet_poll+0x445/0x600 __napi_poll+0x27/0x1e0 net_rx_action+0x2fe/0x3b0 handle_softirqs+0xc2/0x2c0 __irq_exit_rcu+0x74/0xd0 common_interrupt+0x7f/0x90 </IRQ> ... Kernel panic - not syncing: Fatal exception in interrupt After taking a reference, check whether the nulls node is unhashed in both IPv4 and IPv6 established lookups. If it is unhashed or the tuple no longer matches, drop the reference and restart the lookup. Lookups racing with the TIME_WAIT hashdance, or with a request being replaced by its child, now restart and find the new socket instead of returning the old one. Request sockets that were never inserted into ehash can have a nonzero refcount, and a stale lookup can hold a transient reference. Therefore, when SYN cookie, Fast Open, and request migration paths fail after setting a nonzero refcount, release the references held by those paths with reqsk_put() instead of freeing the request directly.

—No exploit Fix available
Published
Nov 10, 2026
Updated
Nov 10, 2026
EPSS
—
CWE
—

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Action score

0

Monitor

Low priority for now.

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

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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

    • 4.4affected
    • 079096f103faca2dd87342cca6f23d4b34da8871 and later · before d69100340b4cae08d40f898f1b601032403f6be6affected · git
    • 079096f103faca2dd87342cca6f23d4b34da8871 and later · before 8e5172cbd227fae32f3313cba1f3e1b9edb5c4fdaffected · git
    • 079096f103faca2dd87342cca6f23d4b34da8871 and later · before eb8a2d156f2c1d862fffdfd1b3432bfbcd939879affected · git
    • before 4.4not affected · semver
    • 6.12.117 and later · up to and including 6.12.*not affected · semver
    • 6.18.63 and later · up to and including 6.18.*not affected · semver
    • 7.3.4 and later · up to and including 7.3.*not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxfrom 0—

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-2026-99285Nov 10, 2026 · netfilter: nft_byteorder: remove multi-register support
    0Monitor
  • ← EarlierCVE-2026-99286Nov 10, 2026 · xen-netback: Fix XenBus connection failure cleanup
    0Monitor
  • ← EarlierCVE-2026-99287Nov 10, 2026 · xen-netback: Zero out sring pointers on unmap
    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 Linux8e5172cbd227fae32f3313cba1f3e1b9edb5c4fdVendor (CNA)
Linux Linuxd69100340b4cae08d40f898f1b601032403f6be6Vendor (CNA)
Linux Linuxeb8a2d156f2c1d862fffdfd1b3432bfbcd939879Vendor (CNA)

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

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  1. Published
  2. Fix recordedsame day
  3. TodayNov 11, 2026+1 d

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

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No commit or PR link among the references.

Credits

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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).

Technical details

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

Weakness class (CWE)

—

Attack context

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Change log

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

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References

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

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