High, CVSS 8.2crates.ioPublished
lz4_flex's decompression can leak information from uninitialized memory or reused output buffer
CVE-2026-32829 · GHSA-vvp9-7p8x-rfvv
- Affected
- crates.io lz4_flex < 0.11.6; >= 0.12.0, < 0.12.1
- Fixed in
- 0.12.10.11.6· Vendor fix available
- Issue
- Decompressing invalid LZ4 data can leak data from uninitialized memory, or can leak content from previous decompression operations when reusing an output buffer. Details The LZ4 block format defines a "match copy operation" which duplicates previously written data or data from the user-supplied dict. The position of that data is defined by an offset. The data is copied within the output buffer from the offset to the current output position. However, lz4flex did not properly detect invalid and out-of-bounds offset values properly, causing it to copy uninitialized data from the output buffer. Only the block based API functions are affected: lz4flex::block::{decompressinto, decompressintowithdict} When safe-decode is disabled additionally these functions are affected lz4flex::block::{decompress, decompresswithdict, decompresssizeprepended, decompresssizeprependedwithdict} All frame APIs are not affected. There are two affected use cases: - decompressing LZ4 data with the unsafe…
Recommended action: Upgrade to 0.12.1 or 0.11.6 by release line, then redeploy and verify.A vendor fix does not resolve your finding until you verify it in your own systems.