CVE-2026-53185 zram: fix use-after-free in zram_bvec_write_partial()
A use-after-free in the Linux kernel zram driver allows attackers to execute arbitrary code or cause a denial of service via crafted write operations.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-53185?
CVE-2026-53185 is a high-severity use after free vulnerability in Linux kernel, published on 25 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.
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.
Which versions are affected by CVE-2026-53185?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-53185?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-53185 being exploited?
There is no known exploitation of CVE-2026-53185 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-90366, BELL-CVE-2026-53185, DEBIAN-CVE-2026-53185, GHSA-4pqw-3h25-qrq3, ROOT-OS-DEBIAN-11-CVE-2026-53185, ROOT-OS-DEBIAN-12-CVE-2026-53185 and 3 more.