CVE-2026-74399 evm: terminate and bound the evm_xattrs read buffer
A local attacker can read uninitialized kernel memory or cause a crash by triggering the EVM xattrs read path when no xattrs are enabled.
- 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-2026-74399?
CVE-2026-74399 is a vulnerability in Linux, published on 15 Aug 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:
evm: terminate and bound the evm_xattrs read buffer
evm_read_xattrs() allocates size + 1 bytes, fills them from the list of enabled xattrs, and then passes strlen(temp) to simple_read_from_buffer(). When no configured xattrs are enabled, the fill loop stores nothing and temp[0] remains uninitialized, so strlen() reads beyond initialized memory.
Explicitly terminate the buffer after allocation, use snprintf() for each formatted line, and pass the accumulated length, without risk of truncation, to simple_read_from_buffer().
Which versions are affected by CVE-2026-74399?
How do I fix CVE-2026-74399?
Apply the vendor's patch.
Is CVE-2026-74399 being exploited?
There is no known exploitation of CVE-2026-74399 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-74399, DEBIAN-CVE-2026-74399, GHSA-vgh3-675w-vhgv, UBUNTU-CVE-2026-74399.