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Vulnerabilities

Vulnerability · CVE-2026-25541

Bytes is a utility library for working with bytes.

Published Feb 4, 2026 · catalog updated Feb 5, 2026 · Bytes is a utility

Last checked Nov 4, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2026-25541. EPSS is 0.60%. Act only if a listed version of Bytes is a utility is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (Bytes is a utility).
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
Medium5.5
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.60%
Remediation
Version ranges on file
Affected products
vendor tokio-rs bytes 1.2.1, < 1.11.1

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

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • vendor tokio-rs bytes 1.2.1, < 1.11.11.2.1, < 1.11.1

How to fix CVE-2026-25541

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-25541. EPSS is 0.60%. Act only if a listed version of Bytes is a utility is installed.

Which versions are affected?

Compare what you have installed with tokio-rs bytes 1.2.1, < 1.11.1 1.2.1, < 1.11.1. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS 0.60%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Feb 4, 2026 · EUVD

    Detected

    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

  2. Feb 5, 2026 · EUVD

    Updated

    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

Sources

  • CVE.orgVulnerability recordCVE-2026-25541

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-25541

    30-day exploitation probability 0.60%

    first.org
  • EUVDVulnerability recordEUVD-2026-5321

    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. Whe

    euvd.enisa.europa.eu

References

Freshness

Last verified in this catalog Nov 4, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • FIRST EPSSNov 4, 2026
  • CVE.orgNov 4, 2026
  • EUVDNov 3, 2026