CVE-2026-35347 uutils coreutils comm Silent Data Loss or Denial of Service via Improper Input Validation
The comm utility in uutils coreutils can cause denial of service or silent data loss when processing non-regular file inputs like FIFOs or pipes.
- 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-2026-35347?
CVE-2026-35347 is a medium-severity denial of service vulnerability in Uutils coreutils, published on 22 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
The comm utility in uutils coreutils incorrectly consumes data from non-regular file inputs before performing comparison operations. The are_files_identical function opens and reads from both input paths to compare content without first verifying if the paths refer to regular files. If an input path is a FIFO or a pipe, this pre-read operation drains the stream, leading to silent data loss before the actual comparison logic is executed. Additionally, the utility may hang indefinitely if it attempts to pre-read from infinite streams like /dev/zero.
Weakness: CWE-20
Which versions are affected by CVE-2026-35347?
2 open source packages ship an affected version, including uu_comm. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
uu_comm crates.io | All versions | 0.6.0 |
uu_comm crates.io | All versions | 0.6.0 |
Products include Uutils Coreutils.
How do I fix CVE-2026-35347?
Upgrade uu_comm to 0.6.0 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-35347 being exploited?
There is no known exploitation of CVE-2026-35347 in the wild and no public exploit code.
Other vulnerabilities in Uutils coreutils
- CVE-2026-35338 uutils coreutils chmod Path Traversal Bypass of --preserve-root
- CVE-2026-35368 uutils coreutils chroot Local Privilege Escalation and chroot Escape in via Name Service Switch (NSS) Injection
- CVE-2026-35341 uutils coreutils mkfifo Unauthorized Permission Change on Existing Files
- CVE-2026-35352 uutils coreutils mkfifo Privilege Escalation via TOCTOU Race Condition
- CVE-2026-35349 uutils coreutils Path-Based Safety Bypass with --preserve-root
Sources
Also known as DEBIAN-CVE-2026-35347, GHSA-3wfc-mgpm-9rq6, UBUNTU-CVE-2026-35347.