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TI-2026-75570 Aliases CVE-2026-98442GHSA-cqvg-rqhw-9mqj

Use-after-free in Linux kernel act_ct helper after extension realloc

Priority LOW 33Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 4 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.

Summary

The Linux kernel from 6.2 is affected. In the net/sched act_ct code, a raw pointer to the extensions area is kept in an expectations list, and later extension additions can reallocate that area, leaving the pointer dangling for use when the expectation is removed. A local user with low privileges can trigger this without user interaction, with high impact on confidentiality, integrity and availability.

Written with Claude Haiku 5.5 from the sources below · 2026-11-06

Description from the CNA

In the Linux kernel, the following vulnerability has been resolved: net/sched: act_ct: fix helper UAF due to extensions realloc While calling the helpers, a raw pointer to the extensions area is wired into expectations list: -> nf_ct_helper() -> helper->help() -> nf_ct_expect_related_report() -> nf_ct_expect_insert() -> hlist_add_head_rcu(&exp->lnode, &master_help->expectations) In case the connection is not confirmed yet, more extensions can be added afterwards with *_ext_add() calls reallocating the extension space and leaving the now invalid pointer in the expectations list that is later accessed while removing the expectation. Make sure that helpers are called at the end after all the other extensions are already added. Note that the helper rejection now leaves the mark and labels set, but that's not different from how the NAT was handled before or how the mark and the labels were handled on confirmation failure. And there are no atomicity guarantees provided by the API anyway.

Why it matters now

EPSS 0.00129 2nd percentileScored 2026-11-07
Fix Partial Linux (Linux): 6.6.160, 6.12.112, 6.18.55 +2Red Hat: 4 without a fix

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
LinuxLinux6.2 and later6.6.160, 6.12.112, 6.18.55, 7.2.9, 7.3Patch availableCNA
  • Linux VendorLinux Affected 6.2 and later Fixed in 6.6.160, 6.12.112, 6.18.55, 7.2.9, 7.3 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*——Linux
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions — — ·Linux

Remediation

The fixed Linux kernel versions are 6.6.160, 6.12.112, 6.18.55, 7.2.9 and 7.3. Red Hat's plan for Red Hat Enterprise Linux 9 and 10, and OpenShift Container Platform 4 and 5, is none_available.

Written with Claude Haiku 5.5 from the sources below · 2026-11-06

  • Fix · CNA Linux (Linux) Fixed in 6.6.160, 6.12.112, 6.18.55, 7.2.9, 7.3

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 10AffectedNo fix yet
Red Hat Enterprise Linux 9AffectedNo fix yet
Red Hat OpenShift Container Platform 4AffectedNo fix yet
Red Hat OpenShift Container Platform 5AffectedNo fix yet
Not affected: 4 products
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 7
  • Red Hat Enterprise Linux 8
  • Red Hat OpenShift Container Platform 4

Timeline

  1. 2026-10-18 Threatist record created from CVE-2026-98442
  2. 2026-10-18 Alias added: GHSA-cqvg-rqhw-9mqj
  3. 2026-10-19 Fix available: Linux/[email protected] · CNA
  4. 2026-10-20 Affected versions changed · Red Hat
  5. 2026-10-20 CVSS score added · Red Hat
  6. 2026-10-21 Fix available: Linux/Linux@31f5fe29a572037ee19c233dfe506849940c484b, Linux/[email protected] · CNA
  7. 2026-10-21 1 new reference · CNA
  8. 2026-10-24 CVSS score added · CNA
  9. 2026-10-30 Affected versions changed · Red Hat

References

Other 5

  • TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
  • TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
  • TI-2021-02452 Incorrect authorization in Ubuntu linux kernel KEVCVSS 3.1HIGH 8.8
  • TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
  • TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
  • TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
See all 21741 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences