---
title: "CVE-2026-63126: Wire - Denial of Service"
description: "Wire protobuf readers prior to 6.4.5 and 7.0.0-alpha04 contain a denial of service vulnerability caused by inconsistent validation of attacker-controlled lengths in protobuf decoding, letting attackers cause crashes or excessive allocation, exploit requires supplying malformed protobuf bytes."
url: https://panop.io/threat-heartbeat/CVE-2026-63126/
---

# CVE-2026-63126 Wire - Denial of Service

Wire protobuf readers prior to 6.4.5 and 7.0.0-alpha04 contain a denial of service vulnerability caused by inconsistent validation of attacker-controlled lengths in protobuf decoding, letting attackers cause crashes or excessive allocation, exploit requires supplying malformed protobuf bytes.

CVSS base score 7.5 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Not required

EPSS

0.82% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-63126)

## Details

Type

Denial of Service

Impact

Denial Of Service

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Published

16 September 2026

Updated

15 October 2026

Weakness

[CWE-190](https://cwe.mitre.org/data/definitions/190.html)

## Vendor fix

Update to versions 6.4.5 or 7.0.0-alpha04 or later.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-63126](https://nvd.nist.gov/vuln/detail/CVE-2026-63126)
- [https://github.com/square/wire/commit/082d5d83cec57ef68f1dd7d3e3d1d641c1fb670f](https://github.com/square/wire/commit/082d5d83cec57ef68f1dd7d3e3d1d641c1fb670f)
- [https://github.com/square/wire/commit/25ebcabb9ab7f12d1d77af75ecbc51726fddc015](https://github.com/square/wire/commit/25ebcabb9ab7f12d1d77af75ecbc51726fddc015)
- [https://github.com/square/wire/pull/3635](https://github.com/square/wire/pull/3635)
- [https://github.com/square/wire/releases/tag/6.4.5](https://github.com/square/wire/releases/tag/6.4.5)
- [https://github.com/square/wire/releases/tag/7.0.0-alpha04](https://github.com/square/wire/releases/tag/7.0.0-alpha04)
- [https://github.com/square/wire/security/advisories/GHSA-9rm7-3qhh-h2mc](https://github.com/square/wire/security/advisories/GHSA-9rm7-3qhh-h2mc)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

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