Linux: Missing Release of Memory after Effective Lifetime
CVE-2026-43074 is a high-severity missing release of memory after effective lifetime 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 902120be4f44947df6311002addc7faf69bdbff1, a6d57084372161f86660bc4607784420e00efe2c, a6566cd33f6f967a7651ebf2ce0dd31572e319cf 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 0.48% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to 902120be4f44947df6311002addc7faf69bdbff1 or a6d57084372161f86660bc4607784420e00efe2c or a6566cd33f6f967a7651ebf2ce0dd31572e319cf or 5b1173b165421561db29f30afc7e97d940a398a9, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.6.136 or 6.12.83 or 6.18.24 or 6.19.14, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | f2451def095c1743adcfcb0cb5dadc86034e162a up to, but not including, 902120be4f44947df6311002addc7faf69bdbff1; a1f93804449d13f97dabd4b996817de4bf1ed67a up to, but not including, a6d57084372161f86660bc4607784420e00efe2c; 58c9b016e12855286370dfb704c08498edbc857a up to, but not including, a6566cd33f6f967a7651ebf2ce0dd31572e319cf; 58c9b016e12855286370dfb704c08498edbc857a up to, but not including, 5b1173b165421561db29f30afc7e97d940a398a9; 58c9b016e12855286370dfb704c08498edbc857a up to, but not including, 7e8083f5eeedab0f460063b9c2c14c9a4e71a427; 58c9b016e12855286370dfb704c08498edbc857a up to, but not including, ae0bb9c1fb7c2594519aeeb096cf2c3b7837b322; 58c9b016e12855286370dfb704c08498edbc857a up to, but not including, 07712db80857d5d09ae08f3df85a708ecfc3b61f; 6.4 | 902120be4f44947df6311002addc7faf69bdbff1, a6d57084372161f86660bc4607784420e00efe2c, a6566cd33f6f967a7651ebf2ce0dd31572e319cf, 5b1173b165421561db29f30afc7e97d940a398a9, 7e8083f5eeedab0f460063b9c2c14c9a4e71a427, ae0bb9c1fb7c2594519aeeb096cf2c3b7837b322 |
| Siemens | SIMATIC S7-1500 TM MFP - GNU/Linux subsystem | all versions | Not stated |
| Linux | Linux Kernel | 6.4.1 up to, but not including, 6.6.136; 6.7 up to, but not including, 6.12.83; 6.13 up to, but not including, 6.18.24; 6.19 up to, but not including, 6.19.14; 6.4; 7.0 | 6.6.136, 6.12.83, 6.18.24, 6.19.14 |
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.
Official description
In the Linux kernel, the following vulnerability has been resolved: eventpoll: defer struct eventpoll free to RCU grace period In certain situations, ep_free() in eventpoll.c will kfree the epi->ep eventpoll struct while it still being used by another concurrent thread. Defer the kfree() to an RCU callback to prevent UAF.
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
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- git.kernel.org/stable/c/07712db80857d5d09ae08f3df85a708ecfc3b61f
- git.kernel.org/stable/c/5b1173b165421561db29f30afc7e97d940a398a9
- git.kernel.org/stable/c/7e8083f5eeedab0f460063b9c2c14c9a4e71a427
- git.kernel.org/stable/c/a6566cd33f6f967a7651ebf2ce0dd31572e319cf
- git.kernel.org/stable/c/ae0bb9c1fb7c2594519aeeb096cf2c3b7837b322
Other references
Recent Missing Release of Memory after Effective Lifetime vulnerabilities
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- 7.5 High severity
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