CVE-2026-25541

7.5 HIGH
Published: February 04, 2026 Modified: February 27, 2026
View on NVD

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.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://github.com/tokio-rs/bytes/releases/tag/v1.11.1
Source: security-advisories@github.com
Product Release Notes
https://github.com/tokio-rs/bytes/security/advisories/GHSA-434x-w66g-qw3r
Source: security-advisories@github.com
Exploit Vendor Advisory
https://rustsec.org/advisories/RUSTSEC-2026-0007.html
Source: security-advisories@github.com
Exploit Third Party Advisory

4 reference(s) from NVD

Quick Stats

CVSS v3 Score
7.5 / 10.0
EPSS (Exploit Probability)
0.0%
5th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

tokio-rs