Vulnerability in Silviucpp Ezstd
CVE-2026-119434
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.
Published .
CVSS v3 metric
CVSS v3 base score 6.2 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- EEF CNA record for CVE-2026-119434 (related, third-party-advisory)
- Introducing commit 6730128 in silviucpp/ezstd (related)
- Fix commit e34f4a4 in silviucpp/ezstd (patch)
- ezstd v1.2.5 release notes (release-notes, related)
- OSV record EEF-CVE-2026-119434 (related)
Frequently asked questions
- What is CVE-2026-119434?
- CVE-2026-119434 is a medium-severity vulnerability in Silviucpp Ezstd, classified under Improper Handling of Highly Compressed Data (Data Amplification). CVSS score: 6.2/10. Published 2026-11-05.
- How severe is CVE-2026-119434?
- Medium severity. CVSS v3 base score is 6.2 out of 10.