Service interruption via nested TLV buffer leak
Published Sep 18, 2026 · Updated Sep 18, 2026
A reference-count leak in Netty's HAProxy PROXY-v2 decoder allows remote attackers to exhaust memory with malformed nested TLV headers. In HAProxyMessage.readNextTLV, an exception path calls the flattened-list releaseTlvs routine on a tree of encapsulated TLVs, leaving grandchild ByteBuf slices retained. Only deployments exposing the PROXY-v2 decoder are reachable, and sustained crafted connections are required to accumulate enough pinned buffers to interrupt service.
Summary
What happened
A reference-count leak in Netty's HAProxy PROXY-v2 decoder allows remote attackers to exhaust memory with malformed nested TLV headers. In HAProxyMessage.readNextTLV, an exception path calls the flattened-list releaseTlvs routine on a tree of encapsulated TLVs, leaving grandchild ByteBuf slices retained. Only deployments exposing the PROXY-v2 decoder are reachable, and sustained crafted connections are required to accumulate enough pinned buffers to interrupt service.
The record
- CVE
- CVE-2026-93564
- Published
- Sep 18, 2026
- Updated
- Sep 18, 2026
- Vendor
- Commonhaus Foundation
- Product
- Red Hat JBoss Enterprise Application Platform 7
- Classifications
- CWE-1035, T1499.003
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 18, 2026CVE publishedPublication date reported by the CVE source.
- Sep 18, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Activity data is delayed. The latest report is Sep 28, 2026.
Weakness, pattern, technique
Public exploit references
- Netty nested-TLV grandchild leak proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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