PT-2026-6320 · Bytes · Bytes

Ksj1230 · Published 2026-01-01 · Updated 2026-03-04 · CVE-2026-25541

Positive Technologies (AI Summary)

CVSS v3.1

7.5

High

Base vector

AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Name of the Vulnerable Software and Affected Versions Bytes versions 1.2.1 through 1.11.0

Description The Bytes library contains a flaw in the BytesMut::reserve function that can lead to an integer overflow. Specifically, an unchecked addition within the reclaim path of BytesMut::reserve can cause the allocated capacity to be incorrectly calculated when new cap + offset overflows a usize value in release builds. This can result in the cap value being set to a value exceeding the actual allocated capacity. Subsequent calls to functions like spare capacity mut() may then create out-of-bounds slices, leading to undefined behavior. This issue is observable in release builds, while debug builds trigger a panic due to overflow checks.

Recommendations Update to Bytes version 1.11.1 or later.

Exploit

Fix

Weakness Enumeration

CWE-680

Related Identifiers

AZL-76691

AZL-76703

AZL-76712

AZL-76715

AZL-76718

AZL-76721

AZL-76752

AZL-78615

CVE-2026-25541

GHSA-434X-W66G-QW3R

RUSTSEC-2026-0007

Affected Products

Bytes

References · 35

• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/25xxx/CVE-2026-25541.json · Exploit
• 🔥 https://rustsec.org/advisories/RUSTSEC-2026-0007.html · Exploit
• https://github.com/tokio-rs/bytes/security/advisories/GHSA-434x-w66g-qw3r · Vendor Advisory
• https://github.com/tokio-rs/bytes/commit/d0293b0e35838123c51ca5dfdf468ecafee4398f · Patch
• https://osv.dev/vulnerability/GHSA-434x-w66g-qw3r · Vendor Advisory
• https://osv.dev/vulnerability/AZL-76721 · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2026-25541 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-25541 · Security Note
• https://cve.org/CVERecord?id=CVE-2026-25541 · Security Note
• https://osv.dev/vulnerability/AZL-76712 · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2026-25541 · Vendor Advisory
• https://ubuntu.com/security/CVE-2026-25541 · Vendor Advisory
• https://osv.dev/vulnerability/RUSTSEC-2026-0007 · Vendor Advisory
• https://osv.dev/vulnerability/DEBIAN-CVE-2026-25541 · Vendor Advisory
• https://osv.dev/vulnerability/AZL-78615 · Vendor Advisory