CVE-2026-25541

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.

CVSS v3 7.5 HIGH

7.5^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/tokio-rs/bytes/commit/d0293b0e35838123c51ca5dfdf468ecafee4398f	Patch
https://github.com/tokio-rs/bytes/releases/tag/v1.11.1	Product Release Notes
https://github.com/tokio-rs/bytes/security/advisories/GHSA-434x-w66g-qw3r	Exploit Vendor Advisory
https://rustsec.org/advisories/RUSTSEC-2026-0007.html	Exploit Third Party Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:tokio-rs:bytes:*:*:*:*:*:rust:*:*

History

No history.

Information

Published : 2026-02-04 22:16

Updated : 2026-02-27 20:13

NVD link : CVE-2026-25541

Mitre link : CVE-2026-25541

CVE.ORG link : CVE-2026-25541

JSON object : View

Products Affected

tokio-rs

bytes

CWE

CWE-680

Integer Overflow to Buffer Overflow

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