CVE-2026-25541

MEDIUM EPSS 42.3%
Published Feb 4, 20265mo ago · Modified Jun 17, 20262w ago
5.5 CVSS 4.0
Medium
Find Similar
Published Feb 4, 2026 5mo ago
Last Modified Jun 17, 2026 2w ago

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.

CVSS Details

Base Score
5.5
Exploitability
—
Impact
—
Vector string
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Attack Vector Local
Attack Complexity Low
Privileges Required None
User Interaction None
Scope X

Threat Intelligence

EPSS Exploit Probability
42.3% percentile
Exploit & Patch Status
Public Exploit Known
Patch Available

Weaknesses 1

CWE-680

Affected Products 1

VendorProductVersionRange
tokio-rsbytes*≥1.2.1  –  <1.11.1

References 4

  • github.com https://github.com/tokio-rs/bytes/commit/d0293b0e35838123c51ca5dfdf468ecafee4398f
    Patch
  • github.com https://github.com/tokio-rs/bytes/releases/tag/v1.11.1
    ProductRelease Notes
  • github.com https://github.com/tokio-rs/bytes/security/advisories/GHSA-434x-w66g-qw3r
    ExploitVendor Advisory
  • rustsec.org https://rustsec.org/advisories/RUSTSEC-2026-0007.html
    ExploitThird Party Advisory

Remediation

  • github.com https://github.com/tokio-rs/bytes/commit/d0293b0e35838123c51ca5dfdf468ecafee4398f
    Patch