CyberSecBulletin
CVE-2026-46289NVD status: Analyzed

Linux: Missing Release of Memory after Effective Lifetime

Published Updated By the CyberSecBulletin desk

CVE-2026-46289 is a critical-severity missing release of memory after effective lifetime 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 3f17500e86d730c76db638bb3ae52f9b5e496c76, e5e22fc9963469e678c4f4bb38d26adcec107f1e, 8fbba6829057979149d1b37d65690c037f3ddf4d 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 0.46% 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 3f17500e86d730c76db638bb3ae52f9b5e496c76 or e5e22fc9963469e678c4f4bb38d26adcec107f1e or 8fbba6829057979149d1b37d65690c037f3ddf4d or 9d38756d0a93b66163554219fa9c3365f40c4035, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 6.6.140 or 6.12.88 or 6.18.30 or 7.0.7, 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
LinuxLinux0185846975339a5c348373aa450a977f5242366b up to, but not including, 3f17500e86d730c76db638bb3ae52f9b5e496c76; 0185846975339a5c348373aa450a977f5242366b up to, but not including, e5e22fc9963469e678c4f4bb38d26adcec107f1e; 0185846975339a5c348373aa450a977f5242366b up to, but not including, 8fbba6829057979149d1b37d65690c037f3ddf4d; 0185846975339a5c348373aa450a977f5242366b up to, but not including, 9d38756d0a93b66163554219fa9c3365f40c4035; 0185846975339a5c348373aa450a977f5242366b up to, but not including, 07b7d66e65d9cfe6b9c2c34aa22cfcaac37a5c45; 6.33f17500e86d730c76db638bb3ae52f9b5e496c76, e5e22fc9963469e678c4f4bb38d26adcec107f1e, 8fbba6829057979149d1b37d65690c037f3ddf4d, 9d38756d0a93b66163554219fa9c3365f40c4035, 07b7d66e65d9cfe6b9c2c34aa22cfcaac37a5c45
LinuxLinux Kernel6.3 up to, but not including, 6.6.140; 6.7 up to, but not including, 6.12.88; 6.13 up to, but not including, 6.18.30; 6.19 up to, but not including, 7.0.76.6.140, 6.12.88, 6.18.30, 7.0.7

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.

Official description

In the Linux kernel, the following vulnerability has been resolved: lib/scatterlist: fix length calculations in extract_kvec_to_sg Patch series "Fix bugs in extract_iter_to_sg()", v3. Fix bugs in the kvec and user variants of extract_iter_to_sg. This series is growing due to useful remarks made by sashiko.dev. The main bugs are: - The length for an sglist entry when extracting from a kvec can exceed the number of bytes in the page. This is obviously not intended. - When extracting a user buffer the sglist is temporarily used as a scratch buffer for extracted page pointers. If the sglist already contains some elements this scratch buffer could overlap with existing entries in the sglist. The series adds test cases to the kunit_iov_iter test that demonstrate all of these bugs. Additionally, there is a memory leak fix for the test itself. The bugs were orignally introduced into kernel v6.3 where the function lived in fs/netfs/iterator.c. It was later moved to lib/scatterlist.c in v6.5. Thus the actual fix is only marked for backports to v6.5+. This patch (of 5): When extracting from a kvec to a scatterlist, do not cross page boundaries. The required length was already calculated but not used as intended. Adjust the copied length if the loop runs out of sglist entries without extracting everything. While there, return immediately from extract_iter_to_sg if there are no sglist entries at all. A subsequent commit will add kunit test cases that demonstrate that the patch is necessary.

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

The underlying weakness: Missing Release of Memory after Effective Lifetime

The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.

How developers prevent this class of flaw

  • Choose a language or tool that provides automatic memory management, or makes manual memory management less error-prone. For example, glibc in Linux provides protection against free of invalid pointers. When using Xcode to target OS X or iOS, enable automatic reference counting (ARC). To help correctly and consistently manage memory when programming in C++, consider using a smart pointer class such as std
  • Use an abstraction library to abstract away risky APIs. Not a complete solution.
  • Consider using the Boehm-Demers-Weiser garbage collector (bdwgc), which can help avoid leaks.

More Missing Release of Memory after Effective Lifetime vulnerabilities (CWE-401)

Timeline

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

References

Recent Missing Release of Memory after Effective Lifetime vulnerabilities

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