CVE-2026-25541: tokio-rs bytes · Integer Overflow to Buffer Overflow
Affects tokio-rs bytesSource CVE Database V5
Not known to be exploited · CVSS 5.5 Medium : upgrade to 1.11.1 when convenient.
Data as of 25 Oct 2026, 19:02 UTC
- EPSS
- 0.6% chance of exploitation in 30 days – higher than 48% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 1.11.1, 1.11
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:PExploitation evidence
Disclosed: evidence found.
CVE published 4 Feb 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.
What to do
Upgrade bytes to 1.11.1; tokio-rs/bytes to 1.11.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| tokio-rsbytes | Affected
| Fixed in
|
crates.iotokio-rs/bytespkg:cargo/tokio-rs/bytesOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A fix is available in version 1.11 of the tokio-rs bytes library. Users and developers should upgrade to version 1.11 or later to remediate this vulnerability. No additional mitigation steps are indicated by the vendor advisory.
Description
CVE-2026-25541 is a medium severity integer overflow vulnerability in the tokio-rs bytes library affecting versions 1.2.1 through 1.11.0. The issue arises in the BytesMut::reserve function where unchecked addition can overflow the usize type in release builds, corrupting the capacity value. This can lead to out-of-bounds slices and undefined behavior, potentially causing memory corruption or crashes. No authentication or user interaction is required to trigger the vulnerability. It has been patched in version 1.11.
References
- github.com/tokio-rs/bytes/security/advisories/GHSA-434x-w66g-qw3r (opens in a new tab)
- github.com/tokio-rs/bytes/commit/d0293b0e35838123c51ca5dfdf468ecafee4398f (opens in a new tab)
- github.com/tokio-rs/bytes/releases/tag/v1.11.1 (opens in a new tab)
- rustsec.org/advisories/RUSTSEC-2026-0007.html (opens in a new tab)