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CVE-2026-63126
Published:September 16, 2026
Updated:October 09, 2026
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
https://github.com/square/wire.git (GITHUB):
Affected version(s) >=3.0.0-alpha03 <6.4.5
Fix Suggestion:
Update to version 6.4.5
com.squareup.wire:wire-runtime-linuxx64 (JAVA):
Affected version(s) >=3.0.0-alpha03 <6.4.5
Fix Suggestion:
Update to version 6.4.5
com.squareup.wire:wire-runtime-iosarm64 (JAVA):
Affected version(s) >=3.0.0-alpha03 <6.4.5
Fix Suggestion:
Update to version 6.4.5
com.squareup.wire:wire-runtime-iosx64 (JAVA):
Affected version(s) >=3.0.0-alpha03 <6.4.5
Fix Suggestion:
Update to version 6.4.5
com.squareup.wire:wire-runtime-macosx64 (JAVA):
Affected version(s) >=3.0.0-alpha03 <6.4.5
Fix Suggestion:
Update to version 6.4.5
com.squareup.wire:wire-runtime-jvm (JAVA):
Affected version(s) >=3.0.0-alpha03 <6.4.5
Fix Suggestion:
Update to version 6.4.5
com.squareup.wire:wire-runtime-js (JAVA):
Affected version(s) >=3.0.0-alpha03 <6.4.5
Fix Suggestion:
Update to version 6.4.5
com.squareup.wire:wire-runtime (JAVA):
Affected version(s) >=1.0.0 <6.4.5
Fix Suggestion:
Update to version 6.4.5
github.com/square/wire (SWIFT):
Affected version(s) >=3.3.0-alpha1 <6.4.5
Fix Suggestion:
Update to version 6.4.5
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CVSS v4
Base Score:
8.7
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
NONE
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
7.5
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Weakness Type (CWE)
Integer Overflow or Wraparound
EPSS
Base Score:
0.82