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TI-2026-38086 Aliases CVE-2026-52999GHSA-vhgw-q6q5-v9w3

netfilter: nfnetlink_osf: fix out-of-bounds read on option matching

Priority MEDIUM 46CWE-125Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
High · None · High
Fix status
Partial Red Hat: 2 without a fix

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

Summary

In the Linux kernel, the following vulnerability has been resolved: netfilter: nfnetlink_osf: fix out-of-bounds read on option matching In nf_osf_match(), the nf_osf_hdr_ctx structure is initialized once and passed by reference to nf_osf_match_one() for each fingerprint checked. During TCP option parsing, nf_osf_match_one() advances the shared ctx->optp pointer. If a fingerprint perfectly matches, the function returns early without restoring ctx->optp to its initial state. If the user has configured NF_OSF_LOGLEVEL_ALL, the loop continues to the next fingerprint. However, because ctx->optp was not restored, the next call to nf_osf_match_one() starts parsing from the end of the options buffer. This causes subsequent matches to read garbage data and fail immediately, making it impossible to log more than one match or logging incorrect matches. Instead of using a shared ctx->optp pointer, pass the context as a constant pointer and use a local pointer (optp) for TCP option traversal. This makes nf_osf_match_one() strictly stateless from the caller's perspective, ensuring every fingerprint check starts at the correct option offset.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00591 48th percentileScored 2026-11-07
Fix Partial Linux (Linux): 4.20, 4.21, 5.10.258 +7Red Hat: 2 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

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

Affected products

VendorProductAffected versionsFixed inStatusSource
LinuxLinux4.19.26 to before 4.20; 4.20.13 to before 4.214.20, 4.21Patch availableCNA
LinuxLinux5.0 and later5.10.258, 5.15.209, 6.1.175, 6.6.141, 6.12.91, 6.18.33, 7.0.10, 7.1Patch availableCNA
  • Linux VendorLinux Affected 4.19.26 to before 4.20; 4.20.13 to before 4.21 Fixed in 4.20, 4.21 Patch available CNA
  • Linux VendorLinux Affected 5.0 and later Fixed in 5.10.258, 5.15.209, 6.1.175, 6.6.141, 6.12.91, 6.18.33, 7.0.10, 7.1 Patch available CNA

CPE configurations NVD · 6

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*4.19.26 to before 4.20; 4.20.13 to before 5.0; 5.0.1 to before 5.10.258; 5.11 to before 5.15.209; 5.16 to before 6.1.175; 6.2 to before 6.6.141; 6.7 to before 6.12.91; 6.13 to before 6.18.33; 6.19 to before 7.0.10VulnerableLinux
cpe:2.3:o:linux:linux_kernel:5.0:-:*:*:*:*:*:*5.0VulnerableLinux
cpe:2.3:o:linux:linux_kernel:5.0:rc5:*:*:*:*:*:*5.0 rc5VulnerableLinux
cpe:2.3:o:linux:linux_kernel:5.0:rc6:*:*:*:*:*:*5.0 rc6VulnerableLinux
cpe:2.3:o:linux:linux_kernel:5.0:rc7:*:*:*:*:*:*5.0 rc7VulnerableLinux
cpe:2.3:o:linux:linux_kernel:5.0:rc8:*:*:*:*:*:*5.0 rc8VulnerableLinux
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 4.19.26 to before 4.20; 4.20.13 to before 5.0; 5.0.1 to before 5.10.258; 5.11 to before 5.15.209; 5.16 to before 6.1.175; 6.2 to before 6.6.141; 6.7 to before 6.12.91; 6.13 to before 6.18.33; 6.19 to before 7.0.10 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:5.0:-:*:*:*:*:*:* Versions 5.0 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:5.0:rc5:*:*:*:*:*:* Versions 5.0 rc5 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:5.0:rc6:*:*:*:*:*:* Versions 5.0 rc6 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:5.0:rc7:*:*:*:*:*:* Versions 5.0 rc7 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:5.0:rc8:*:*:*:*:*:* Versions 5.0 rc8 Vulnerable ·Linux

Remediation

  • Fix · CNA Linux (Linux) Fixed in 4.20, 4.21
  • Fix · CNA Linux (Linux) Fixed in 5.10.258, 5.15.209, 6.1.175, 6.6.141, 6.12.91, 6.18.33, 7.0.10, 7.1

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
Red Hat Enterprise Linux 10AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 9AffectedNo fix yet: Fix deferred
Not affected: 3 products
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 7
  • Red Hat Enterprise Linux 8

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-52999
  2. 2026-10-03 Alias added: GHSA-vhgw-q6q5-v9w3
  3. 2026-10-09 EPSS moved to the below the 50th percentile
  4. 2026-10-16 CISA SSVC decision points changed
  5. 2026-10-19 Weakness changed · CISA ADP

References

Patch 8

  • 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