SB2026061984 - Multiple vulnerabilities in IBM Voice Gateway
Published: June 19, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 2 vulnerabilities.
1) Null Byte Interaction Error (Poison Null Byte) (CVE-ID: CVE-2026-42579)
CWE-ID: CWE-626 - Null Byte Interaction Error (Poison Null Byte)
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
The vulnerability allows a remote attacker to bypass domain validation and poison DNS caches.
The vulnerability exists due to improper input validation in io.netty.handler.codec.dns.DnsCodecUtil encodeDomainName() when encoding user-influenced domain names. A remote attacker can supply a crafted domain name containing null bytes, overlength labels, or empty labels to bypass domain validation and poison DNS caches.
The issue affects the encoder path and relies on applications using user-influenced hostnames to construct DNS queries.
2) Allocation of Resources Without Limits or Throttling (CVE-ID: CVE-2026-42583)
CWE-ID: CWE-770 - Allocation of Resources Without Limits or Throttling
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to uncontrolled resource consumption in io.netty.handler.codec.compression.Lz4FrameDecoder#decode when processing crafted LZ4 frames. A remote attacker can send a specially crafted compressed frame header and payload to cause a denial of service.
On the compressed path, header fields are trusted for sizing, allowing a small request to force allocation of a much larger ByteBuf.
Remediation
Install update from vendor's website.