CVE-2026-45859

In the Linux kernel, the following vulnerability has been resolved: netfilter: nfnetlink_queue: do shared-unconfirmed check before segmentation Ulrich reports a regression with nfqueue: If an application did not set the 'F_GSO' capability flag and a gso packet with an unconfirmed nf_conn entry is received all packets are now dropped instead of queued, because the check happens after skb_gso_segment(). In that case, we did have exclusive ownership of the skb and its associated conntrack entry. The elevated use count is due to skb_clone happening via skb_gso_segment(). Move the check so that its peformed vs. the aggregated packet. Then, annotate the individual segments except the first one so we can do a 2nd check at reinject time. For the normal case, where userspace does in-order reinjects, this avoids packet drops: first reinjected segment continues traversal and confirms entry, remaining segments observe the confirmed entry. While at it, simplify nf_ct_drop_unconfirmed(): We only care about unconfirmed entries with a refcnt > 1, there is no need to special-case dying entries. This only happens with UDP. With TCP, the only unconfirmed packet will be the TCP SYN, those aren't aggregated by GRO. Next patch adds a udpgro test case to cover this scenario.
Configurations

Configuration 1 (hide)

OR cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.11:-:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.11:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.11:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.11:rc6:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.11:rc7:*:*:*:*:*:*

History

30 Oct 2026, 13:18

Type Values Removed Values Added
References
  • () https://git.kernel.org/stable/c/4666688657e1054278b836b825fb88b2907e2da2 -

21 Oct 2026, 13:18

Type Values Removed Values Added
References
  • () https://git.kernel.org/stable/c/aead84bdacd77e08357fd718e5dcaffaf387f3c3 -

19 Oct 2026, 20:18

Type Values Removed Values Added
CWE CWE-400

Information

Published : 2026-05-27 14:16

Updated : 2026-10-30 13:18


NVD link : CVE-2026-45859

Mitre link : CVE-2026-45859

CVE.ORG link : CVE-2026-45859


JSON object : View

Products Affected

linux

  • linux_kernel
CWE
NVD-CWE-noinfo CWE-400

Uncontrolled Resource Consumption