CyberSecBulletin
CVE-2026-52989NVD status: Modified

Linux: Use of Uninitialized Resource

Published Updated By the CyberSecBulletin desk

CVE-2026-52989 is a critical-severity use of uninitialized resource vulnerability in Linux, with a CVSS 3.1 base score of 9.8 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 3df42a854686fa06484e37ac1a3931c8e3e3453c, d7c8f95f599b3b38a717d2e771c3f8c174f657c3, f9204a2b78dd18374d3bcf9bf93d9021ce22de1b 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 0.36% chance of exploitation within 30 days, which is low compared with other CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update Linux to 3df42a854686fa06484e37ac1a3931c8e3e3453c or d7c8f95f599b3b38a717d2e771c3f8c174f657c3 or f9204a2b78dd18374d3bcf9bf93d9021ce22de1b or c2a11441538bdbbc5aa003f190995eba93a89b88, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 5.11 or 5.16 or 6.1.175 or 6.6.141, 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
LinuxLinux1385be357e8acd09b36e026567f3a9d5c61139de up to, but not including, 3df42a854686fa06484e37ac1a3931c8e3e3453c; dca1a6ba0da9f472ef040525fab10fd9956db59f up to, but not including, d7c8f95f599b3b38a717d2e771c3f8c174f657c3; 19672ae68d52ff75347ebe2420dde1b07adca09f up to, but not including, f9204a2b78dd18374d3bcf9bf93d9021ce22de1b; ab200d71553bdcf4de554a5985b05b2dd606bc57 up to, but not including, c2a11441538bdbbc5aa003f190995eba93a89b88; 52a0a98549344ca20ad81a4176d68d28e3c05a5c up to, but not including, 046fa5c72d15cd8e2d592e275697ea399d8f76b0; 52a0a98549344ca20ad81a4176d68d28e3c05a5c up to, but not including, ea8e356acb165cb1fd75537a52e1f66e5e76c538; 043b4307a99f902697349128fde93b2ddde4686c; 42afe8ed8ad2de9c19457156244ef3e1eca94b5d; and 7 more ranges3df42a854686fa06484e37ac1a3931c8e3e3453c, d7c8f95f599b3b38a717d2e771c3f8c174f657c3, f9204a2b78dd18374d3bcf9bf93d9021ce22de1b, c2a11441538bdbbc5aa003f190995eba93a89b88, 046fa5c72d15cd8e2d592e275697ea399d8f76b0, ea8e356acb165cb1fd75537a52e1f66e5e76c538
Red HatRed Hat Enterprise Linux 10Not specified in the recordNot stated
Red HatRed Hat Enterprise Linux 6Not specified in the recordNot stated
Red HatRed Hat Enterprise Linux 7Not specified in the recordNot stated
Red HatRed Hat Enterprise Linux 8Not specified in the recordNot stated
Red HatRed Hat Enterprise Linux 9Not specified in the recordNot stated
LinuxLinux Kernel5.10.250 up to, but not including, 5.11; 5.15.200 up to, but not including, 5.16; 6.1.163 up to, but not including, 6.1.175; 6.6.124 up to, but not including, 6.6.141; 6.12.70 up to, but not including, 6.12.91; 6.18.10 up to, but not including, 6.18.33; 6.19.1 up to, but not including, 7.0.10; 6.19; and 1 more ranges5.11, 5.16, 6.1.175, 6.6.141, 6.12.91, 6.18.33

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
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

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

Scoring systemScoreSeverityScored by
CVSS 3.19.8CriticalCNA
CVSS 3.17.1HighCNA

Official description

In the Linux kernel, the following vulnerability has been resolved: nvmet-tcp: propagate nvmet_tcp_build_pdu_iovec() errors to its callers Currently, when nvmet_tcp_build_pdu_iovec() detects an out-of-bounds PDU length or offset, it triggers nvmet_tcp_fatal_error(cmd->queue) and returns early. However, because the function returns void, the callers are entirely unaware that a fatal error has occurred and that the cmd->recv_msg.msg_iter was left uninitialized. Callers such as nvmet_tcp_handle_h2c_data_pdu() proceed to blindly overwrite the queue state with queue->rcv_state = NVMET_TCP_RECV_DATA Consequently, the socket receiving loop may attempt to read incoming network data into the uninitialized iterator. Fix this by shifting the error handling responsibility to the callers.

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

The underlying weakness: Use of Uninitialized Resource

The product uses or accesses a resource that has not been initialized.

How developers prevent this class of flaw

  • Explicitly initialize the resource before use. If this is performed through an API function or standard procedure, follow all required steps.
  • Pay close attention to complex conditionals that affect initialization, since some branches might not perform the initialization.
  • Avoid race conditions (CWE-362) during initialization routines.

More Use of Uninitialized Resource vulnerabilities (CWE-908)

Timeline

  1. CVE record published.
  2. Record last changed materially (score, affected products, status or references).

References

Third-party and government advisories

Recent Use of Uninitialized Resource vulnerabilities

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