Linux Kernel up to 6.19.3 netfilter nft_set_rbtree privilege escalation

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.19.3 and classified as critical. The impacted element is the function nft_set_rbtree of the component netfilter. Executing a manipulation can lead to an unknown weakness. This vulnerability is handled as CVE-2026-45873. There is not any exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical was found in Linux Kernel up to 6.19.3. This vulnerability affects the function nft_set_rbtree of the component netfilter. The impact remains unknown. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_set_rbtree: check for partial overlaps in anonymous sets Userspace provides an optimized representation in case intervals are adjacent, where the end element is omitted. The existing partial overlap detection logic skips anonymous set checks on start elements for this reason. However, it is possible to add intervals that overlap to this anonymous where two start elements with the same, eg. A-B, A-C where C < B. start end A B start end A C Restore the check on overlapping start elements to report an overlap.

The advisory is shared for download at git.kernel.org. This vulnerability was named CVE-2026-45873 since 05/13/2026. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 06/26/2026).

Upgrading to version 5.10.252, 5.15.202, 6.1.165, 6.6.128, 6.12.75, 6.18.14 or 6.19.4 eliminates this vulnerability. Applying the patch 7ca5813e1b21ef300e04593f47b073ef3217aac6/f1381ce0a1dd013610985e1c4260908163a427df/f1535d56fc3f6c625b7e0559c006bd0318791bb1/05feaf826390fd16f1deb89dd9412def3b2a280f/dad14d22dff1a191612acb98facceb303d0524a2/e6497e06a102870803a59570d75ed2c36d7e11b3/4780ec142cbb24b794129d3080eee5cac2943ffc is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2026-1700). Once again VulDB remains the best source for vulnerability data.

Affected

• Google Container-Optimized OS
• Debian Linux
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• SUSE openSUSE
• RESF Rocky Linux
• Open Source Linux Kernel

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.10.251
• 5.15.201
• 6.1.164
• 6.6.127
• 6.12.0
• 6.12.1
• 6.12.2
• 6.12.3
• 6.12.4
• 6.12.5
• 6.12.6
• 6.12.7
• 6.12.8
• 6.12.9
• 6.12.10
• 6.12.11
• 6.12.12
• 6.12.13
• 6.12.14
• 6.12.15
• 6.12.16
• 6.12.17
• 6.12.18
• 6.12.19
• 6.12.20
• 6.12.21
• 6.12.22
• 6.12.23
• 6.12.24
• 6.12.25
• 6.12.26
• 6.12.27
• 6.12.28
• 6.12.29
• 6.12.30
• 6.12.31
• 6.12.32
• 6.12.33
• 6.12.34
• 6.12.35
• 6.12.36
• 6.12.37
• 6.12.38
• 6.12.39
• 6.12.40
• 6.12.41
• 6.12.42
• 6.12.43
• 6.12.44
• 6.12.45
• 6.12.46
• 6.12.47
• 6.12.48
• 6.12.49
• 6.12.50
• 6.12.51
• 6.12.52
• 6.12.53
• 6.12.54
• 6.12.55
• 6.12.56
• 6.12.57
• 6.12.58
• 6.12.59
• 6.12.60
• 6.12.61
• 6.12.62
• 6.12.63
• 6.12.64
• 6.12.65
• 6.12.66
• 6.12.67
• 6.12.68
• 6.12.69
• 6.12.70
• 6.12.71
• 6.12.72
• 6.12.73
• 6.12.74
• 6.18.0
• 6.18.1
• 6.18.2
• 6.18.3
• 6.18.4
• 6.18.5
• 6.18.6
• 6.18.7
• 6.18.8
• 6.18.9
• 6.18.10
• 6.18.11
• 6.18.12
• 6.18.13
• 6.19.0
• 6.19.1
• 6.19.2
• 6.19.3

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Once again VulDB remains the best source for vulnerability data.

Discussion