CVE-2026-74438 crypto: sun4i-ss - Remove insecure and unused rng_alg
A buffer overflow in the unused sun4i-ss random number generator allows potential code execution or denial of service, fixed by removing the insecure code.
- 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-2026-74438?
CVE-2026-74438 is a high-severity memory corruption 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:
crypto: sun4i-ss - Remove insecure and unused rng_alg
Remove sun4i_ss_rng, as it is insecure and unused:
- It has multiple vulnerabilities. sun4i_ss_prng_seed() is missing locking and has a buffer overflow. sun4i_ss_prng_generate() fails to fill the entire buffer with cryptographic random bytes, because it rounds the destination length down and also doesn't actually wait for the hardware to be ready before pulling bytes from it.
- No user of this code is known. It's usable only theoretically via the "rng" algorithm type of AF_ALG. But userspace actually just uses the actual Linux RNG (/dev/random etc) instead. And rng_algs don't contribute entropy to the actual Linux RNG either. (This may have been confused with hwrng, which does contribute entropy.)
The sun4i_ss_prng_seed() buffer overflow was reported by Tianchu Chen and discovered by Atuin - Automated Vulnerability Discovery Engine
There's no point in fixing all these vulnerabilities individually when this is unused code, so let's just remove it.
Which versions are affected by CVE-2026-74438?
How do I fix CVE-2026-74438?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-74438 being exploited?
There is no known exploitation of CVE-2026-74438 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-74438, DEBIAN-CVE-2026-74438, GHSA-pqhh-48h7-jg73, UBUNTU-CVE-2026-74438.