CVE-2026-42582
Netty: HTTP/3 QPACK literal unbounded allocation
CVSS Score
7.5
EPSS Score
0.0%
EPSS Percentile
0th
Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final, when decoding header blocks, the non-Huffman branch of io.netty.handler.codec.http3.QpackDecoder#decodeHuffmanEncodedLiteral may execute new byte[length] for a string literal before verifying that length bytes are actually present in the compressed field section. The wire encoding allows a very large length to be expressed in few bytes. There is no check that length <= in.readableBytes() before new byte[length]. This vulnerability is fixed in 4.2.13.Final.
| CWE | CWE-770 CWE-789 |
| Vendor | netty |
| Product | netty |
| Published | May 13, 2026 |
| Last Updated | May 13, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
Affected Versions
netty / netty
>= 4.2.0.Alpha1, < 4.2.13.Final
io.netty / netty-codec-http3
>= 4.2.0.Alpha1, < 4.2.13.Final