# CVE-2026-45799: Square Wire denial of service in wire-runtime skipGroup

Source: https://junglewise.ai/threats/cve-2026-45799-square-wire-denial-of-service-in-wire-runtime-skipgroup  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-17. Updated: 2026-07-17  
License: CC BY 4.0 with a link back

CVE-2026-45799 · Severity: high · CVSS 7.5 · Published 2026-07-17

Square Wire, a library used for handling gRPC and protocol buffers in mobile and Java applications, contains a flaw in how it processes certain data messages. An attacker can send a specially crafted message that causes the application to crash unexpectedly. This can lead to a denial-of-service (DoS) condition, disrupting services that rely on this library to process external data.

Technologies: [com.squareup.wire:wire-runtime (Maven)](https://junglewise.ai/threats/technologies/com-squareup-wire-wire-runtime). Vendors: [Maven](https://junglewise.ai/threats/vendors/maven).

## Quick answers

**Is CVE-2026-45799 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-45799 being exploited in the wild.

**How severe is CVE-2026-45799?** High severity, with a CVSS score of 7.5, published 17 July 2026.

**Which products and versions are affected?** com.squareup.wire:wire-runtime (Maven) ECOSYSTEM:introduced=0,fixed=6.3.0; com.squareup.wire:wire-runtime-jvm (Maven) ECOSYSTEM:introduced=0,fixed=6.3.0.

**Is there a fix for CVE-2026-45799?** Yes. com.squareup.wire:wire-runtime (Maven): upgrade to 6.3.0 or later; com.squareup.wire:wire-runtime-jvm (Maven): upgrade to 6.3.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-45799 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-45799?** Check whether you run com.squareup.wire:wire-runtime (Maven), com.squareup.wire:wire-runtime-jvm (Maven), Square Wire Runtime or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- com.squareup.wire:wire-runtime (Maven): upgrade to 6.3.0 or later

  ```sh
  # set com.squareup.wire:wire-runtime to 6.3.0 in your pom.xml or build.gradle
  ```

- com.squareup.wire:wire-runtime-jvm (Maven): upgrade to 6.3.0 or later

  ```sh
  # set com.squareup.wire:wire-runtime-jvm to 6.3.0 in your pom.xml or build.gradle
  ```


## Technical details

A vulnerability exists in the ByteArrayProtoReader32.skipGroup() and ProtoReader.skipGroup() functions within the wire-runtime component. The root cause is a failure to validate that a LENGTH_DELIMITED field length is non-negative before calling the skip() method. An attacker can provide a crafted protobuf varint encoding -128 as a signed integer, which causes the internal reader position to become negative. Subsequent read operations then trigger an unhandled ArrayIndexOutOfBoundsException instead of the expected IOException or ProtocolException. This results in a service crash when decoding untrusted payloads via ProtoAdapter.decode(byte[]). The issue is resolved in versions 6.3.0 and 7.0.0-alpha03.

## Affected products

- Square wire-runtime < 6.3.0, >= 7.0.0-alpha01, < 7.0.0-alpha03

## Identifiers

- CVE-2026-45799
- GHSA-7xpr-hc2w-34m9

## Timeline

- 2026-05-12: patched: Fix merged into master branch
- 2026-05-13: patched: Fix merged into 6.x branch and version 6.3.0 released
- 2026-05-14: advisory: GitHub Security Advisory published
- 2026-07-17: disclosed: CVE published to NVD

## References

- [https://github.com/square/wire/commit/47d5b0dba53935d5332cd41a80a353b3fc90e7b0](https://github.com/square/wire/commit/47d5b0dba53935d5332cd41a80a353b3fc90e7b0)
- [https://github.com/square/wire/commit/e4e56fab38a547d9625f05c97f1d8f0bcc3a5773](https://github.com/square/wire/commit/e4e56fab38a547d9625f05c97f1d8f0bcc3a5773)
- [https://github.com/square/wire/pull/3595](https://github.com/square/wire/pull/3595)
- [https://github.com/square/wire/pull/3597](https://github.com/square/wire/pull/3597)
- [https://github.com/square/wire/releases/tag/6.3.0](https://github.com/square/wire/releases/tag/6.3.0)
- [https://github.com/square/wire/releases/tag/7.0.0-alpha03](https://github.com/square/wire/releases/tag/7.0.0-alpha03)
- [https://github.com/square/wire/security/advisories/GHSA-7xpr-hc2w-34m9](https://github.com/square/wire/security/advisories/GHSA-7xpr-hc2w-34m9)

## Related threats

- [Wire protobuf decoder integer overflow denial of service](https://junglewise.ai/threats/cve-2026-63126-wire-protobuf-decoder-integer-overflow-denial-of-service)
- [Wire has Uncontrolled Recursion on Nested Groups](https://junglewise.ai/threats/cve-2024-58103-wire-has-uncontrolled-recursion-on-nested-groups)