CVE-2026-25541
📋 TL;DR
This vulnerability in the Bytes library allows integer overflow in the BytesMut::reserve function, which can cause memory corruption and out-of-bounds memory access. Applications using vulnerable versions of the Bytes library (1.2.1 through 1.11.0) in Rust projects are affected, particularly when running in release mode where integer overflow wraps instead of panicking.
💻 Affected Systems
- tokio-rs/bytes library
⚠️ Risk & Real-World Impact
Worst Case
Memory corruption leading to arbitrary code execution, denial of service, or data leakage through out-of-bounds memory access.
Likely Case
Application crashes, memory corruption, or undefined behavior leading to denial of service.
If Mitigated
Limited impact if running in debug mode (which panics on overflow) or with proper memory safety controls.
🎯 Exploit Status
Exploitation requires triggering the specific integer overflow condition in BytesMut::reserve, which depends on application usage patterns.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.11.1
Vendor Advisory: https://github.com/tokio-rs/bytes/security/advisories/GHSA-434x-w66g-qw3r
Restart Required: Yes
Instructions:
1. Update Cargo.toml to specify bytes = "^1.11.1" or higher. 2. Run 'cargo update' to fetch the patched version. 3. Rebuild and redeploy your application.
🔧 Temporary Workarounds
Run in debug mode
allDebug builds panic on integer overflow instead of wrapping, preventing the vulnerability from being triggered.
cargo build
cargo run
Pin to safe version
allForce dependency resolution to use a safe version of bytes library.
cargo update -p bytes --precise 1.11.1
🧯 If You Can't Patch
- Run applications in debug mode where possible to trigger panic on overflow
- Implement additional memory safety checks in application code using the bytes library
🔍 How to Verify
Check if Vulnerable:
Check Cargo.lock or run 'cargo tree | grep bytes' to see if bytes version is between 1.2.1 and 1.11.0.Check Version:
cargo tree | grep bytesVerify Fix Applied:
Verify bytes version is 1.11.1 or higher in Cargo.lock with 'cargo tree | grep bytes'.📡 Detection & Monitoring
Log Indicators:
- Application crashes with memory access violations
- Unexpected panics in release builds
- Memory corruption errors
Network Indicators:
- Sudden service unavailability
- Increased error rates in HTTP responses
SIEM Query:
Search for application logs containing 'panicked at', 'memory access violation', or 'out of bounds' errors from Rust applications.