CVE-2025-58057 Netty's BrotliDecoder is vulnerable to DoS via zip bomb style attack
Attackers can cause denial of service in Netty applications by sending crafted input that triggers excessive memory allocation in the BrotliDecoder.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-58057?
CVE-2025-58057 is a medium-severity denial of service vulnerability in Netty Netty, published on 3 Sep 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Netty is an asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers & clients. In netty-codec-compression versions 4.1.124.Final and below, and netty-codec versions 4.2.4.Final and below, when supplied with specially crafted input, BrotliDecoder and certain other decompression decoders will allocate a large number of reachable byte buffers, which can lead to denial of service. BrotliDecoder.decompress has no limit in how often it calls pull, decompressing data 64K bytes at a time. The buffers are saved in the output list, and remain reachable until OOM is hit. This is fixed in versions 4.1.125.Final of netty-codec and 4.2.5.Final of netty-codec-compression.
Weakness: CWE-409
Which versions are affected by CVE-2025-58057?
4 open source packages ship an affected version, including io.netty:netty-codec and io.netty:netty-codec-compression. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
io.netty:netty-codec Maven | All versions | 4.1.125.Final |
io.netty:netty-codec Maven | All versions | 4.1.125.Final |
io.netty:netty-codec-compression Maven | From 4.2.0.Alpha1 | 4.2.5.Final |
io.netty:netty-codec-compression Maven | From 4.2.0.Alpha1 | 4.2.5.Final |
Products include Netty Netty.
How do I fix CVE-2025-58057?
Upgrade io.netty:netty-codec to 4.1.125.Final or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2025-58057 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-58057 exists.
Other vulnerabilities in Netty Netty
- CVE-2026-75595 Netty: SNI Routing Bypass via Fragmented TLS ClientHello Causing Fallback to Default SslContext
- CVE-2026-75596 Netty: Fragmented ClientHello records trigger quadratic pre-handshake reassembly in default SNI parsing
- CVE-2026-59901 Netty Bzip2Decoder: Infinite Loop in RLE State Machine Leads to Event-Loop Thread Hang
- CVE-2026-55851 Netty codec-haproxy: Signed-Byte Sentinel Collision in HAProxyMessageDecoder Leads to Unbounded Memory Exhaustion
- CVE-2026-56745 Netty SpdyHttpDecoder: ByteBuf Reference Leak on RST_STREAM Leads to Native Memory Exhaustion
Sources
Also known as CLEANSTART-2026-DD70897, CLEANSTART-2026-DW10612, CLEANSTART-2026-HA94391, CLEANSTART-2026-TU89159, CLEANSTART-2026-UI06484, CLSA-2026-1777336751 and 54 more.