CVE-2026-53185: Linux kernel · zram: fix use-after-free in zram_bvec_write_partial()
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.8 High · fixed in c96786d6ff1acc1d54d9241e97767554c1dfdd5b : patch Linux kernel soon.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 1% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Total control over the software or total information disclosure
CISA SSVC assessment, 2026-10-16.
- Patch
- Available – fixed in c96786d6ff1acc1d54d9241e97767554c1dfdd5b, 732fd9f0b9c1cdc6dfd77162ded60df005182cc0, 198b5a14cca27263b9c14b20114c8092de15dfcb +2
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 25 Jun 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in– |
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.
References
- git.kernel.org/stable/c/0c2821665ff71be3f4b07ecece384669f2877f6a (opens in a new tab)
- git.kernel.org/stable/c/77a602b505ce4802915853cfc435a4722fab3e64 (opens in a new tab)
- git.kernel.org/stable/c/c96786d6ff1acc1d54d9241e97767554c1dfdd5b (opens in a new tab)
- git.kernel.org/stable/c/198b5a14cca27263b9c14b20114c8092de15dfcb (opens in a new tab)
- git.kernel.org/stable/c/732fd9f0b9c1cdc6dfd77162ded60df005182cc0 (opens in a new tab)
- access.redhat.com/security/cve/CVE-2026-53185 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2492735 (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-53185.json (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:61887 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:65708 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:59723 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:63014 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:63013 (opens in a new tab)