CVE-2026-119434 Decompression bomb in ezstd:decompress_using_ddict/2 allows BEAM memory exhaustion via unbounded output buffer
- Exploited in the wild
- Not known
- Fix
- Available
What is CVE-2026-119434?
CVE-2026-119434 is a medium-severity vulnerability in silviucpp ezstd, published on 5 Nov 2026.
Official description
Improper Handling of Highly Compressed Data (Data Amplification) vulnerability in silviucpp ezstd allows an attacker who supplies a zstd frame to ezstd:decompress_using_ddict/2 to exhaust memory and terminate the Erlang VM via a small frame that declares a very large content size.
zstd_nif_decompress_using_ddict in c_src/ezstd_nif.cc reads the frame's declared content size with ZSTD_getFrameContentSize and passes it directly to enif_make_new_binary, without the 1 GiB MAX_BUFFER_SIZE check that ezstd:decompress/1 applies before allocating. A valid 65,550-byte frame of RLE blocks declaring 2 GiB is rejected by ezstd:decompress/1 but is fully allocated and decompressed by the dictionary path. The allocation happens inside a NIF, so when it exceeds the memory available to the VM the operating system kills the whole node rather than the calling process.
This issue affects ezstd: from 1.0.5 before 1.2.5.
Weakness: CWE-409
Which versions are affected by CVE-2026-119434?
1 open source package ship an affected version, including ezstd.
| Package | Affected | Fixed in |
|---|---|---|
ezstd Hex | From 1.0.5 | 1.2.5 |
How do I fix CVE-2026-119434?
Upgrade ezstd to 1.2.5 or later.
Is CVE-2026-119434 being exploited?
There is no known exploitation of CVE-2026-119434 in the wild and no public exploit code.
Sources
Also known as EEF-CVE-2026-119434, GHSA-p9j8-93gx-5h3x.