Linux: Use After Free
CVE-2026-53185 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 0c2821665ff71be3f4b07ecece384669f2877f6a, 77a602b505ce4802915853cfc435a4722fab3e64, c96786d6ff1acc1d54d9241e97767554c1dfdd5b 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 0.11% 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 0c2821665ff71be3f4b07ecece384669f2877f6a or 77a602b505ce4802915853cfc435a4722fab3e64 or c96786d6ff1acc1d54d9241e97767554c1dfdd5b or 198b5a14cca27263b9c14b20114c8092de15dfcb, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.6.143 or 6.12.94 or 6.18.36 or 7.0.13, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 8e654f8fbff52ac483fb69957222853d7e2fc588 up to, but not including, 0c2821665ff71be3f4b07ecece384669f2877f6a; 8e654f8fbff52ac483fb69957222853d7e2fc588 up to, but not including, 77a602b505ce4802915853cfc435a4722fab3e64; 8e654f8fbff52ac483fb69957222853d7e2fc588 up to, but not including, c96786d6ff1acc1d54d9241e97767554c1dfdd5b; 8e654f8fbff52ac483fb69957222853d7e2fc588 up to, but not including, 198b5a14cca27263b9c14b20114c8092de15dfcb; 8e654f8fbff52ac483fb69957222853d7e2fc588 up to, but not including, 732fd9f0b9c1cdc6dfd77162ded60df005182cc0; 4.14 | 0c2821665ff71be3f4b07ecece384669f2877f6a, 77a602b505ce4802915853cfc435a4722fab3e64, c96786d6ff1acc1d54d9241e97767554c1dfdd5b, 198b5a14cca27263b9c14b20114c8092de15dfcb, 732fd9f0b9c1cdc6dfd77162ded60df005182cc0 |
| Red Hat | Red Hat Enterprise Linux 10 | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 8 | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 9 | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 6 | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 7 | Not specified in the record | Not stated |
| Linux | Linux Kernel | 4.14 up to, but not including, 6.6.143; 6.7 up to, but not including, 6.12.94; 6.13 up to, but not including, 6.18.36; 6.19 up to, but not including, 7.0.13; 7.1 | 6.6.143, 6.12.94, 6.18.36, 7.0.13 |
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 system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.8 | High | CNA |
| CVSS 3.1 | 7.0 | High | CNA |
Official description
In the Linux kernel, the following vulnerability has been resolved: zram: fix use-after-free in zram_bvec_write_partial() zram_read_page() picks the sync or async backing device read path based on whether the parent bio is NULL. zram_bvec_write_partial() passes its parent bio down, so for ZRAM_WB slots the read is dispatched asynchronously and zram_read_page() returns 0 while the bio is still in flight. The caller then runs memcpy_from_bvec(), zram_write_page() and __free_page() on the buffer, leaving the async read to write into a freed page. zram_bvec_read_partial() was switched to NULL in commit 4e3c87b9421d ("zram: fix synchronous reads") for the same reason; the write_partial counterpart was missed.
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.
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/0c2821665ff71be3f4b07ecece384669f2877f6a
- git.kernel.org/stable/c/198b5a14cca27263b9c14b20114c8092de15dfcb
- git.kernel.org/stable/c/732fd9f0b9c1cdc6dfd77162ded60df005182cc0
- git.kernel.org/stable/c/77a602b505ce4802915853cfc435a4722fab3e64
- git.kernel.org/stable/c/c96786d6ff1acc1d54d9241e97767554c1dfdd5b
Third-party and government advisories
- access.redhat.com/security/cve/CVE-2026-53185Third Party Advisory
- bugzilla.redhat.com/show_bug.cgi?id=2492735Issue Tracking, Third Party Advisory
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-53185.jsonThird Party Advisory
Other references
Recent Use After Free vulnerabilities
- 7.5 High severity
- 9.8 Critical severity
- 7.8 High severity
- 7.8 High severity
- 7.5 High severity
- 8.2 High severity
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