Vulnerability · Published Jul 17, 2026 · Assigned by GitHub_M
CVE-2026-45799Wire: skipGroup() missing negative-length check allows 10-byte payload to crash any Wire-decoding service
High 7.5
In plain English
A high-severity security flaw in wire from square. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 54% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Wire provides gRPC and protocol buffers for Android, Kotlin, Swift, and Java. Prior to 6.3.0 and 7.0.0-alpha03, ByteArrayProtoReader32.skipGroup() and ProtoReader.skipGroup() in wire-runtime do not validate that a LENGTH_DELIMITED field length is non-negative before skip(), allowing a crafted protobuf varint encoding -128 as a signed Int to make skip(-128) move the internal position negative and make the next readByte() throw ArrayIndexOutOfBoundsException instead of the documented IOException or ProtocolException, which can crash services using ProtoAdapter.decode(byte[]) on untrusted payloads. This issue is fixed in versions 6.3.0 and 7.0.0-alpha03.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Maven | com.squareup.wire:wire-runtime | 6.3.0 | GHSA-7xpr-hc2w-34m9 |
| Maven | com.squareup.wire:wire-runtime | 7.0.0-alpha03 | GHSA-7xpr-hc2w-34m9 |
| Maven | com.squareup.wire:wire-runtime-jvm | 7.0.0-alpha03 | GHSA-7xpr-hc2w-34m9 |
| Maven | com.squareup.wire:wire-runtime-jvm | 6.3.0 | GHSA-7xpr-hc2w-34m9 |
| Ubuntu:22.04:LTS | grpc | no fix listed | UBUNTU-CVE-2026-45799 |
| Ubuntu:24.04:LTS | grpc | no fix listed | UBUNTU-CVE-2026-45799 |
| Ubuntu:26.04:LTS | grpc | no fix listed | UBUNTU-CVE-2026-45799 |
| Ubuntu:26.10 | grpc | no fix listed | UBUNTU-CVE-2026-45799 |
Affected products (as reported)
Weakness: CWE-129 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
References
- https://github.com/square/wire/security/advisories/GHSA-7xpr-hc2w-34m9 x_refsource_CONFIRM
- https://github.com/square/wire/pull/3595 x_refsource_MISC
- https://github.com/square/wire/pull/3597 x_refsource_MISC
- https://github.com/square/wire/commit/47d5b0dba53935d5332cd41a80a353b3fc90e7b0 x_refsource_MISC
- https://github.com/square/wire/commit/e4e56fab38a547d9625f05c97f1d8f0bcc3a5773 x_refsource_MISC
- https://github.com/square/wire/releases/tag/6.3.0 x_refsource_MISC
- https://github.com/square/wire/releases/tag/7.0.0-alpha03 x_refsource_MISC