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NVD / CVE Program· CNA Linux

CVE-2026-74268: tcp: clear sock_ops cb flags before force-closing a child socket

Noroxi assessment

Priority: Monitor (action score 39/100)

  • 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: 0.71% (FIRST EPSS); higher than 53.9% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: Linux Linux 5d5389b2c37ca00da61d1407618ebe15abae0c8b, 71e9c53220abd7f5a45aa4d5e5b420d3479f3a4f, 8874dafc9099bc49c2e5ebba030f85d276421f92; azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 6.6.157.1-1.

Low priority for now. Upgrade to Linux Linux 5d5389b2c37ca00da61d1407618ebe15abae0c8b, 71e9c53220abd7f5a45aa4d5e5b420d3479f3a4f, 8874dafc9099bc49c2e5ebba030f85d276421f92; azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 6.6.157.1-1 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: tcp: clear sock_ops cb flags before force-closing a child socket A child socket inherits the listener's bpf_sock_ops_cb_flags via sk_clone_lock(). If its setup fails in tcp_v4_syn_recv_sock() / tcp_v6_syn_recv_sock(), the child is freed through put_and_exit, where inet_csk_prepare_forced_close() drops the socket lock and tcp_done() runs without it. If BPF_SOCK_OPS_STATE_CB_FLAG was inherited, tcp_done() -> tcp_set_state() calls tcp_call_bpf(), which expects the lock and trips sock_owned_by_me(): WARNING: include/net/sock.h:1799 at tcp_set_state+0x433/0x550 RIP: 0010:tcp_set_state+0x433/0x550 include/net/sock.h:1799 Call Trace: <IRQ> tcp_done+0xba/0x250 net/ipv4/tcp.c:5095 tcp_v4_syn_recv_sock+0x850/0xa50 net/ipv4/tcp_ipv4.c:1787 tcp_check_req+0xf30/0x1360 net/ipv4/tcp_minisocks.c:926 tcp_v4_rcv+0x1047/0x1b50 net/ipv4/tcp_ipv4.c:2164 </IRQ> The child is freed before it is ever established, so it should run no sock_ops callback. Clear its cb flags in inet_csk_prepare_for_destroy_sock(), the common point for the IPv4, IPv6 and chtls forced-close paths and for the MPTCP ->syn_recv_sock() failure path (dispose_child), which reaches tcp_done() on a child that was never established too.

CriticalCVSS 9.8 · v3.1—No exploit Fix available
Published
Aug 15, 2026
Updated
Oct 16, 2026
EPSS
0.7% · 53th percentile
CWE
—

Report tools

JSON

Action score

39

Monitor

Low priority for now.

CVSS
39 / 40 · 9.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.7%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · Linux
9.8
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-74268

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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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

    • 4.16affected
    • d44874910a26f3a8f81edf873a2473363f07f660 and later · before 5d5389b2c37ca00da61d1407618ebe15abae0c8baffected · git
    • d44874910a26f3a8f81edf873a2473363f07f660 and later · before 9f30ba9aa0270a18fdd1e6cd426c480c35f7de9daffected · git
    • d44874910a26f3a8f81edf873a2473363f07f660 and later · before 71e9c53220abd7f5a45aa4d5e5b420d3479f3a4faffected · git
    • d44874910a26f3a8f81edf873a2473363f07f660 and later · before 9fffa6465851a1910a6e9cb7272787dd615b26b1affected · git
    • d44874910a26f3a8f81edf873a2473363f07f660 and later · before fe23d56e9266d58ba5c380f1970118eedeee0b68affected · git
    • d44874910a26f3a8f81edf873a2473363f07f660 and later · before ce311bd2e36596f0aa2c92ca86fb3e019ac57eaeaffected · git
    • d44874910a26f3a8f81edf873a2473363f07f660 and later · before 8874dafc9099bc49c2e5ebba030f85d276421f92affected · git
    • d44874910a26f3a8f81edf873a2473363f07f660 and later · before 990348e5bb457697c2f1f7f7b65154a3334d9d2baffected · git
    • before 4.16not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.190-16.1.190-1
Debian:12linux-6.12before 6.12.111-1~deb12u16.12.111-1~deb12u1
Debian:13linuxbefore 6.12.111-16.12.111-1
Debian:14linuxbefore 7.1.5-17.1.5-1

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-2026-74265Aug 15, 2026 · net: mana: initialize gdma queue id to INVALID_QUEUE_ID
    0Monitor
  • ← EarlierCVE-2026-74267Aug 15, 2026 · net/sched: sch_codel: Do not call qdisc_tree_reduce_backlog during peek before restoring qlen
    39Monitor
  • Later →CVE-2026-74269Aug 15, 2026 · bnxt: fix head underflow on XDP head-grow
    39Monitor

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 Linux5d5389b2c37ca00da61d1407618ebe15abae0c8bVendor (CNA)
Linux Linux71e9c53220abd7f5a45aa4d5e5b420d3479f3a4fVendor (CNA)
Linux Linux8874dafc9099bc49c2e5ebba030f85d276421f92Vendor (CNA)
Linux Linux990348e5bb457697c2f1f7f7b65154a3334d9d2bVendor (CNA)
Linux Linux9f30ba9aa0270a18fdd1e6cd426c480c35f7de9dVendor (CNA)
Linux Linux9fffa6465851a1910a6e9cb7272787dd615b26b1Vendor (CNA)
Linux Linuxce311bd2e36596f0aa2c92ca86fb3e019ac57eaeVendor (CNA)
Linux Linuxfe23d56e9266d58ba5c380f1970118eedeee0b68Vendor (CNA)
azl3 kernel 6.6.150.1-1 on Azure Linux 3.0—Microsoft (MSRC)
azl3 kernel 6.6.152.1-1 on Azure Linux 3.06.6.157.1-1 · Release NotesMicrosoft (MSRC)
debian:linux6.1.190-1 · Debian:12Package registry (OSV)
debian:linux6.12.111-1 · Debian:13Package registry (OSV)
debian:linux-6.126.12.111-1~deb12u1 · Debian:12Package 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.

No dated events beyond publication.

EPSS, last 120 days+1% in 7 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).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

—

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

nvd-secondary

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. SSVC exploitation— → 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