Vulnerability · Published Sep 16, 2026 · Assigned by GitHub_M
CVE-2026-63126Wire: Unauthenticated decoder crash via 32-bit length integer overflow in ByteArrayProtoReader32 (incomplete fix of CVE-2026-45799)
High 7.5
In plain English
A high-severity integer overflow in wire from square. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.8% (higher than 58% 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 6.4.5 and 7.0.0-alpha04, Wire protobuf readers do not consistently validate attacker-controlled lengths against the current logical message boundary before advancing cursors, pointers, limits, slices, or allocations. In Kotlin, ProtoAdapter.decode(ByteArray) and ProtoAdapter.decode(ByteString) use ByteArrayProtoReader32.internalNextLengthDelimited(), where a positive oversized length can wrap pos + length to a negative limit and escape the existing negative-length check. Related ProtoReader, ReadBuffer.readVarint(), ReadBuffer.verifyAdditional(count:), packed-repeated, nested-message, and ProtoDecoder.decodeSizeDelimited(_:from:) paths can cross logical boundaries, perform pointer arithmetic, reserve capacity, or convert an unrepresentable size before proving the requested bytes exist. An attacker who supplies malformed protobuf bytes can cause unchecked exceptions, traps, out-of-bounds behavior, or excessive allocation, resulting in denial of service without known confidentiality, integrity, or code-execution impact. This issue is fixed in versions 6.4.5 and 7.0.0-alpha04.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Maven | com.squareup.wire:wire-runtime | 6.4.5 | GHSA-9rm7-3qhh-h2mc |
| Maven | com.squareup.wire:wire-runtime | 7.0.0-alpha04 | GHSA-9rm7-3qhh-h2mc |
Affected products (as reported)
Weakness: CWE-190 · 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-9rm7-3qhh-h2mc x_refsource_CONFIRM
- https://github.com/square/wire/pull/3635 x_refsource_MISC
- https://github.com/square/wire/commit/082d5d83cec57ef68f1dd7d3e3d1d641c1fb670f x_refsource_MISC
- https://github.com/square/wire/commit/25ebcabb9ab7f12d1d77af75ecbc51726fddc015 x_refsource_MISC
- https://github.com/square/wire/releases/tag/6.4.5 x_refsource_MISC
- https://github.com/square/wire/releases/tag/7.0.0-alpha04 x_refsource_MISC