CyberSecBulletin
CVE-2026-45984NVD status: Modified

Linux: Use After Free

Published Updated By the CyberSecBulletin desk

CVE-2026-45984 is a high-severity use after free vulnerability in Linux, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions 1403989d1b502f4a2c0d0b42ccf1c25748442eff, 1cae1bafdf9caa9b462b19af06b1a06902e4e142, 764c3c84b5683e608f43735c803a5f415046686c 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 0.18% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux to 1403989d1b502f4a2c0d0b42ccf1c25748442eff or 1cae1bafdf9caa9b462b19af06b1a06902e4e142 or 764c3c84b5683e608f43735c803a5f415046686c or d87268326b277af3665237ac76a73dd9fa8e21b4, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 5.10.252 or 5.15.202 or 6.1.165 or 6.6.128, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinuxd0a22a4b03b8475b7aa3fa41243c26c291407844 up to, but not including, 1403989d1b502f4a2c0d0b42ccf1c25748442eff; d0a22a4b03b8475b7aa3fa41243c26c291407844 up to, but not including, 1cae1bafdf9caa9b462b19af06b1a06902e4e142; d0a22a4b03b8475b7aa3fa41243c26c291407844 up to, but not including, 764c3c84b5683e608f43735c803a5f415046686c; d0a22a4b03b8475b7aa3fa41243c26c291407844 up to, but not including, d87268326b277af3665237ac76a73dd9fa8e21b4; d0a22a4b03b8475b7aa3fa41243c26c291407844 up to, but not including, 87d4954b5c59735a99ea98cb208d47130f6dce7d; d0a22a4b03b8475b7aa3fa41243c26c291407844 up to, but not including, 6d76febba07c40bcf358f63216d36ea68cf1c215; d0a22a4b03b8475b7aa3fa41243c26c291407844 up to, but not including, 815ddd27c0c7171a99fe802fdb19098ddef8b19d; d0a22a4b03b8475b7aa3fa41243c26c291407844 up to, but not including, faddeb848305e79db89ee0479bb0e33380656321; and 1 more ranges1403989d1b502f4a2c0d0b42ccf1c25748442eff, 1cae1bafdf9caa9b462b19af06b1a06902e4e142, 764c3c84b5683e608f43735c803a5f415046686c, d87268326b277af3665237ac76a73dd9fa8e21b4, 87d4954b5c59735a99ea98cb208d47130f6dce7d, 6d76febba07c40bcf358f63216d36ea68cf1c215
Red HatRed Hat Enterprise Linux 10Not specified in the recordNot stated
Red HatRed Hat Enterprise Linux 7 Extended Lifecycle SupportNot specified in the recordNot stated
Red HatRed Hat Enterprise Linux 8Not specified in the recordNot stated
Red HatRed Hat Enterprise Linux 8.6 Advanced Mission Critical Update SupportNot specified in the recordNot stated
Red HatRed Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-OnNot specified in the recordNot stated
Red HatRed Hat Enterprise Linux 8.8 Telecommunications Update ServiceNot specified in the recordNot stated
Red HatRed Hat Enterprise Linux 8.8 Update Services for SAP SolutionsNot specified in the recordNot stated
Red HatRed Hat Enterprise Linux 9Not specified in the recordNot stated
Red HatRed Hat Enterprise Linux 9.2 Update Services for SAP SolutionsNot specified in the recordNot stated
Red HatRed Hat Enterprise Linux 9.4 Update Services for SAP SolutionsNot specified in the recordNot stated
Red HatRed Hat Enterprise Linux 9.6 Extended Update SupportNot specified in the recordNot stated
Red HatRed Hat Enterprise Linux 6Not specified in the recordNot stated
Red HatRed Hat Enterprise Linux for NVIDIA 26Not specified in the recordNot stated
Red HatRed Hat OpenShift Container Platform 4Not specified in the recordNot stated
LinuxLinux Kernel5.2 up to, but not including, 5.10.252; 5.11 up to, but not including, 5.15.202; 5.16 up to, but not including, 6.1.165; 6.2 up to, but not including, 6.6.128; 6.7 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, 6.19.45.10.252, 5.15.202, 6.1.165, 6.6.128, 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
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
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:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CNA.

Scoring systemScoreSeverityScored by
CVSS 3.17.8HighCNA
CVSS 3.17.8HighCNA

Official description

In the Linux kernel, the following vulnerability has been resolved: gfs2: Fix use-after-free in iomap inline data write path The inline data buffer head (dibh) is being released prematurely in gfs2_iomap_begin() via release_metapath() while iomap->inline_data still points to dibh->b_data. This causes a use-after-free when iomap_write_end_inline() later attempts to write to the inline data area. The bug sequence: 1. gfs2_iomap_begin() calls gfs2_meta_inode_buffer() to read inode metadata into dibh 2. Sets iomap->inline_data = dibh->b_data + sizeof(struct gfs2_dinode) 3. Calls release_metapath() which calls brelse(dibh), dropping refcount to 0 4. kswapd reclaims the page (~39ms later in the syzbot report) 5. iomap_write_end_inline() tries to memcpy() to iomap->inline_data 6. KASAN detects use-after-free write to freed memory Fix by storing dibh in iomap->private and incrementing its refcount with get_bh() in gfs2_iomap_begin(). The buffer is then properly released in gfs2_iomap_end() after the inline write completes, ensuring the page stays alive for the entire iomap operation. Note: A C reproducer is not available for this issue. The fix is based on analysis of the KASAN report and code review showing the buffer head is freed before use. [agruenba: Take buffer head reference in gfs2_iomap_begin() to avoid leaks in gfs2_iomap_get() and gfs2_iomap_alloc().]

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

The underlying weakness: Use After Free

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.

How developers prevent this class of flaw

  • Choose a language that provides automatic memory management.
  • When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.

More Use After Free vulnerabilities (CWE-416)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Use After Free vulnerabilities

Spotted an error? Tell us.