CVE-2026-25541
HIGHBytes 1.2.1-1.11.0 - Integer Overflow to Buffer Overflow in BytesMut::reserve
Title source: llmExploitation Summary
EIP tracks 2 public exploits for CVE-2026-25541. PoCs published by trajanOx, hanyvert.
AI-analyzed exploit summary Detailed technical analysis of CVE-2026-25541, an integer overflow in the Rust `bytes` crate (versions 1.2.1 to 1.11.0) leading to out-of-bounds memory writes. The writeup explains how the vulnerability affects the `fuel-block-committer` service via EigenDA blob fragment processing, with potential for RCE and signing key extraction.
Description
Bytes is a utility library for working with bytes. From version 1.2.1 to before 1.11.1, Bytes is vulnerable to integer overflow in BytesMut::reserve. In the unique reclaim path of BytesMut::reserve, if the condition "v_capacity >= new_cap + offset" uses an unchecked addition. When new_cap + offset overflows usize in release builds, this condition may incorrectly pass, causing self.cap to be set to a value that exceeds the actual allocated capacity. Subsequent APIs such as spare_capacity_mut() then trust this corrupted cap value and may create out-of-bounds slices, leading to UB. This behavior is observable in release builds (integer overflow wraps), whereas debug builds panic due to overflow checks. This issue has been patched in version 1.11.1.
Exploits (2)
Detailed technical analysis of CVE-2026-25541, an integer overflow in the Rust `bytes` crate (versions 1.2.1 to 1.11.0) leading to out-of-bounds memory writes. The writeup explains how the vulnerability affects the `fuel-block-committer` service via EigenDA blob fragment processing, with potential for RCE and signing key extraction.
This repository provides a detailed technical analysis of CVE-2026-25541, an integer overflow vulnerability in the `bytes` Rust crate affecting FuelLabs' fuel-block-committer. It includes root cause analysis, affected code paths, and a minimal PoC demonstrating the overflow.
References (4)
Scores
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H