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TI-2020-18865 Aliases CVE-2020-36694GHSA-7prr-xcc8-8wpv

An issue was discovered in netfilter in the Linux kernel before 5.10.

Priority HIGH 65CWE-416Published · Updated

Key facts

Attack vector
Local
Privileges required
High
User interaction
None
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 4 fixed, 1 without a fix

Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat. Impact type from CWE-416 and the CVSS impact.

Summary

An issue was discovered in netfilter in the Linux kernel before 5.10. There can be a use-after-free in the packet processing context, because the per-CPU sequence count is mishandled during concurrent iptables rules replacement. This could be exploited with the CAP_NET_ADMIN capability in an unprivileged namespace. NOTE: cc00bca was reverted in 5.12.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00444 38th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Partial Red Hat: 2 advisoriesRed Hat: 4 fixed, 1 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
——all versions—No fix listedCNA
  • — Vendor— Affected all versions Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*before 5.10VulnerableLinux
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions before 5.10 Vulnerable ·Linux

Remediation

Red Hat 2 advisories

  • RHSA-2021:1739 Released 2021-05-18 · Red Hat rating Important
    kernel-rt security and bug fix update
    • Red Hat Enterprise Linux Real Time (v. 8) kernel-rt-4.18.0-305.rt7.72.el8, kernel-rt-core-4.18.0-305.rt7.72.el8, kernel-rt-debug-4.18.0-305.rt7.72.el8 +7
    • Red Hat Enterprise Linux Real Time for NFV (v. 8) kernel-rt-4.18.0-305.rt7.72.el8, kernel-rt-core-4.18.0-305.rt7.72.el8, kernel-rt-debug-4.18.0-305.rt7.72.el8 +9
  • RHSA-2021:1578 Released 2021-05-18 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat CodeReady Linux Builder (v. 8) kernel-tools-libs-devel-4.18.0-305.el8
    • Red Hat Enterprise Linux BaseOS (v. 8) bpftool-4.18.0-305.el8, kernel-4.18.0-305.el8, kernel-abi-stablelists-4.18.0-305.el8 +19

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
Red Hat Enterprise Linux 7AffectedNo fix planned: Out of support scope
Red Hat CodeReady Linux Builder (v. 8)Fixed RHSA-2021:1578
Red Hat Enterprise Linux BaseOS (v. 8)Fixed RHSA-2021:1578
Red Hat Enterprise Linux Real Time (v. 8)Fixed RHSA-2021:1739
Red Hat Enterprise Linux Real Time for NFV (v. 8)Fixed RHSA-2021:1739
Not affected: 2 products
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 9

Timeline

  1. 2026-10-02 Threatist record created from CVE-2020-36694
  2. 2026-10-03 Alias added: GHSA-7prr-xcc8-8wpv

References

Exploit 1

Patch 1

Other 3

  • 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-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
  • TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
See all 15278 →

Sources

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