CyberSecBulletin
CVE-2026-45859NVD status: Modified

Linux: Uncontrolled Resource Consumption

Published Updated By the CyberSecBulletin desk

CVE-2026-45859 is a high-severity uncontrolled resource consumption vulnerability in Linux, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 4666688657e1054278b836b825fb88b2907e2da2, aead84bdacd77e08357fd718e5dcaffaf387f3c3, 79b713ef4261a8ead96af4703f89d0b5f25532e2 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.71% chance of exploitation within 30 days, higher than 54% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux to 4666688657e1054278b836b825fb88b2907e2da2 or aead84bdacd77e08357fd718e5dcaffaf387f3c3 or 79b713ef4261a8ead96af4703f89d0b5f25532e2 or 23901aa6b8a2f294c4b774436b4691f3ff863a8f, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 5.16 or 6.2 or 6.7 or 6.11, whichever matches your release line, or a later version.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux6dcc8ba8a6074bb79040f502dc66ad23a58a1c86 up to, but not including, 4666688657e1054278b836b825fb88b2907e2da2; 74e6eb7fd27ef1ccc68041dbc66e6d80d2e4a1a0 up to, but not including, aead84bdacd77e08357fd718e5dcaffaf387f3c3; 7d8dc1c7be8d3509e8f5164dd5df64c8e34d7eeb up to, but not including, 79b713ef4261a8ead96af4703f89d0b5f25532e2; 7d8dc1c7be8d3509e8f5164dd5df64c8e34d7eeb up to, but not including, 23901aa6b8a2f294c4b774436b4691f3ff863a8f; 7d8dc1c7be8d3509e8f5164dd5df64c8e34d7eeb up to, but not including, b740e7ddd7ca0dbfeafca3f5e52717206cf28524; 7d8dc1c7be8d3509e8f5164dd5df64c8e34d7eeb up to, but not including, 207b3ebacb6113acaaec0d171d5307032c690004; 6c4a0ba674f410ab99a30a16f32dac0ebfed5cd3; 025b3326c5c409b372d0103ad30f174e55adbd1b; and 5 more ranges4666688657e1054278b836b825fb88b2907e2da2, aead84bdacd77e08357fd718e5dcaffaf387f3c3, 79b713ef4261a8ead96af4703f89d0b5f25532e2, 23901aa6b8a2f294c4b774436b4691f3ff863a8f, b740e7ddd7ca0dbfeafca3f5e52717206cf28524, 207b3ebacb6113acaaec0d171d5307032c690004
LinuxLinux Kernel5.15.166 up to, but not including, 5.16; 6.1.107 up to, but not including, 6.2; 6.6.48 up to, but not including, 6.7; 6.10.7 up to, but not including, 6.11; 6.11.1 up to, but not including, 6.12.75; 6.13 up to, but not including, 6.18.14; 6.19 up to, but not including, 6.19.4; 6.115.16, 6.2, 6.7, 6.11, 6.12.75, 6.18.14

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
NoneNo data is disclosed.
Integrity
NoneNothing can be modified.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by CNA.

Official description

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.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Uncontrolled Resource Consumption

The product does not properly control the allocation and maintenance of a limited resource.

How developers prevent this class of flaw

  • Ensure that protocols have specific limits of scale placed on them.
  • Ensure that all failures in resource allocation place the system into a safe posture.

More Uncontrolled Resource Consumption vulnerabilities (CWE-400)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Uncontrolled Resource Consumption vulnerabilities

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