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.
Project Subscriptions
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Advisories
| Source | ID | Title |
|---|---|---|
Github GHSA |
GHSA-434x-w66g-qw3r | bytes has integer overflow in BytesMut::reserve |
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Wed, 04 Feb 2026 22:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | |
| Title | Bytes is vulnerable to integer overflow in BytesMut::reserve | |
| Weaknesses | CWE-680 | |
| References |
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| Metrics |
cvssV4_0
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Projects
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Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-02-04T22:03:53.554Z
Reserved: 2026-02-02T19:59:47.375Z
Link: CVE-2026-25541
No data.
Status : Received
Published: 2026-02-04T22:16:00.383
Modified: 2026-02-04T22:16:00.383
Link: CVE-2026-25541
No data.
OpenCVE Enrichment
No data.
Weaknesses
Github GHSA