{"id":"CVE-2026-32829","aliases":["DEBIAN-CVE-2026-32829","EUVD-2026-13426","GHSA-vvp9-7p8x-rfvv","RUSTSEC-2026-0041","UBUNTU-CVE-2026-32829"],"status":"published","title":"lz4_flex: Decompression can leak information from uninitialized memory or reused output buffer","description":"lz4_flex is a pure Rust implementation of LZ4 compression/decompression. In versions 0.11.5 and below, and 0.12.0,  decompressing invalid LZ4 data can leak sensitive information from uninitialized memory or from previous decompression operations. The library fails to properly validate offset values during LZ4 \"match copy operations,\" allowing out-of-bounds reads from the output buffer. The block-based API functions (`decompress_into`, `decompress_into_with_dict`, and others when `safe-decode` is disabled) are affected, while all frame APIs are unaffected. The impact is potential exposure of sensitive data and secrets through crafted or malformed LZ4 input. This issue has been fixed in versions 0.11.6 and 0.12.1.","severity":{"version":"4.0","score":8.2,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00633,"percentile":0.50621,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-201","CWE-823"],"published":"2026-03-16T20:48:08Z","modified":"2026-10-28T02:30:31Z","fixes":[{"ecosystem":"crates.io","package":"lz4_flex","fixed_in":["0.11.6","0.12.1"],"sources":["ghsa","osv"]},{"ecosystem":"Debian:14","package":"rust-lz4-flex","fixed_in":["0.13.0-1"],"sources":["osv"]}],"affected":[{"source":"ghsa","ecosystem":"crates.io","package":"lz4_flex","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.11.6"}]}]},{"source":"ghsa","ecosystem":"crates.io","package":"lz4_flex","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0.12.0"},{"fixed":"0.12.1"}]}]},{"source":"osv","ecosystem":"Debian:13","package":"rust-lz4-flex","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.11.3-1","0.11.3-2","0.13.0-1"]},{"source":"osv","ecosystem":"Debian:14","package":"rust-lz4-flex","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.13.0-1"}]}],"versions":["0.11.3-1","0.11.3-2"]},{"source":"osv","ecosystem":"crates.io","package":"lz4_flex","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"0.11.6"}]}]},{"source":"osv","ecosystem":"crates.io","package":"lz4_flex","ranges":[{"type":"SEMVER","events":[{"introduced":"0.12.0"},{"fixed":"0.12.1"}]}]},{"source":"osv","ecosystem":"crates.io","package":"lz4_flex","ranges":[{"type":"SEMVER","events":[{"introduced":"0.0.0-0"},{"fixed":"0.11.6"},{"introduced":"0.12.0"},{"fixed":"0.12.1"}]}]},{"source":"osv","ecosystem":"Ubuntu:24.04:LTS","package":"rust-lz4-flex","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.11.1-1"]},{"source":"osv","ecosystem":"Ubuntu:25.10","package":"rust-lz4-flex","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.11.3-1"]},{"source":"osv","ecosystem":"Ubuntu:26.10","package":"rust-lz4-flex","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.11.3-2","0.13.0-1"]},{"source":"osv","ecosystem":"Ubuntu:26.04:LTS","package":"rust-lz4-flex","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.11.3-1","0.11.3-2"]}],"products":[{"vendor":"pseitz","product":"lz4_flex"},{"vendor":"red hat","product":"logging subsystem for red hat openshift 6.2"},{"vendor":"red hat","product":"logging subsystem for red hat openshift 6.4"},{"vendor":"red hat","product":"logging subsystem for red hat openshift 6.5"},{"vendor":"red hat","product":"openshift lightspeed"},{"vendor":"red hat","product":"red hat ansible automation platform 2"},{"vendor":"red hat","product":"red hat enterprise linux 10"},{"vendor":"red hat","product":"red hat enterprise linux 9"},{"vendor":"red hat","product":"red hat openshift ai (rhoai)"},{"vendor":"red hat","product":"red hat openshift ai 3.3"}],"references":[{"url":"https://github.com/PSeitz/lz4_flex/security/advisories/GHSA-vvp9-7p8x-rfvv","tags":["x_refsource_CONFIRM","Mitigation","Vendor Advisory","advisory","web"]},{"url":"https://github.com/PSeitz/lz4_flex/commit/055502ee5d297ecd6bf448ac91c055c7f6df9b6d","tags":["x_refsource_MISC","Patch","fix","web"]},{"url":"https://rustsec.org/advisories/RUSTSEC-2026-0041.html","tags":["x_refsource_MISC","Third Party Advisory","advisory","web","report"]},{"url":"https://access.redhat.com/security/cve/CVE-2026-32829","tags":["vdb-entry","x_refsource_REDHAT","advisory"]},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2448271","tags":["issue-tracking","x_refsource_REDHAT","report"]},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-32829.json","tags":["x_sadp-csaf-vex","web"]},{"url":"https://access.redhat.com/errata/RHSA-2026:22862","tags":["vendor-advisory","x_refsource_REDHAT","advisory"]},{"url":"https://access.redhat.com/errata/RHSA-2026:16354","tags":["vendor-advisory","x_refsource_REDHAT","advisory"]},{"url":"https://access.redhat.com/errata/RHSA-2026:11800","tags":["vendor-advisory","x_refsource_REDHAT","advisory"]},{"url":"https://access.redhat.com/errata/RHSA-2026:19712","tags":["vendor-advisory","x_refsource_REDHAT","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-32829","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-vvp9-7p8x-rfvv","tags":["report"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/32xxx/CVE-2026-32829.json","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-32829","tags":["advisory"]},{"url":"https://github.com/PSeitz/lz4_flex","tags":["package"]},{"url":"https://crates.io/crates/lz4_flex","tags":["package"]},{"url":"https://ubuntu.com/security/CVE-2026-32829","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-32829","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2026-32829","title":"lz4_flex: Decompression can leak information from uninitialized memory or reused output buffer","description":"lz4_flex is a pure Rust implementation of LZ4 compression/decompression. In versions 0.11.5 and below, and 0.12.0,  decompressing invalid LZ4 data can leak sensitive information from uninitialized memory or from previous decompression operations. The library fails to properly validate offset values during LZ4 \"match copy operations,\" allowing out-of-bounds reads from the output buffer. The block-based API functions (`decompress_into`, `decompress_into_with_dict`, and others when `safe-decode` is disabled) are affected, while all frame APIs are unaffected. The impact is potential exposure of sensitive data and secrets through crafted or malformed LZ4 input. This issue has been fixed in versions 0.11.6 and 0.12.1.","status":"published","published":"2026-03-20T00:49:12.893Z","modified":"2026-09-17T12:04:33.082Z","cvss":[{"version":"4.0","score":8.2,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","level":"high","assessor":"cna"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"high","assessor":"adp"}],"cwes":["CWE-201","CWE-823","CWE-823"],"updated_at":"2026-11-02T14:19:57.47301Z"}],"euvd":[{"id":"EUVD-2026-13426","description":"lz4_flex is a pure Rust implementation of LZ4 compression/decompression. In versions 0.11.5 and below, and 0.12.0,  decompressing invalid LZ4 data can leak sensitive information from uninitialized memory or from previous decompression operations. The library fails to properly validate offset values during LZ4 \"match copy operations,\" allowing out-of-bounds reads from the output buffer. The block-based API functions (`decompress_into`, `decompress_into_with_dict`, and others when `safe-decode` is disabled) are affected, while all frame APIs are unaffected. The impact is potential exposure of sensitive data and secrets through crafted or malformed LZ4 input. This issue has been fixed in versions 0.11.6 and 0.12.1.","status":"published","published":"2026-03-20T00:49:12Z","modified":"2026-09-17T12:04:33Z","cvss":[{"version":"4.0","score":8.2,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","level":"high"}],"updated_at":"2026-11-02T17:28:13.536818Z"}],"ghsa":[{"id":"GHSA-vvp9-7p8x-rfvv","title":"lz4_flex's decompression can leak information from uninitialized memory or reused output buffer","description":"### Summary\nDecompressing invalid LZ4 data can leak data from uninitialized memory, or can leak content from previous decompression operations when reusing an output buffer.\n\n### Details\nThe 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.\nHowever, lz4_flex did not properly detect invalid and out-of-bounds _offset_ values properly, causing it to copy uninitialized data from the output buffer.\n\nOnly the block based API functions are affected: \n`lz4_flex::block::{decompress_into, decompress_into_with_dict}`\n\nWhen safe-decode is disabled _additionally_ these functions are affected\n`lz4_flex::block::{decompress, decompress_with_dict, decompress_size_prepended, decompress_size_prepended_with_dict}`\n\nAll `frame` APIs are _not_ affected.\n\nThere are two affected use cases:\n- decompressing LZ4 data with the `unsafe` implementation (`safe-decode` feature flag disabled, which is enabled by default):\ncan leak content of uninitialized memory as decompressed result\n- decompressing LZ4 data into a reused, user-supplied `output` buffer (affects the `safe-decode` feature as well):\ncan leak the previous contents of the output buffer as decompressed result\n\n### Impact\nLeakage of data from uninitialized memory or content from previous decompression operations, possibly revealing sensitive information and secrets.\n\n### Mitigation\nlz4_flex 0.12.1 and 0.11.6 fixes this issue without requiring changes in user code.\n\nIf you cannot upgrade, you can mitigate this vulnerability by zeroing the output buffer before calling `block::decompress_into` or  `block::decompress_into_with_dict` (only block based API is affected, frame API is not affected). Additionally the the `safe-decode` feature flag should be enabled.","status":"published","published":"2026-03-16T20:48:08Z","modified":"2026-03-20T21:18:56Z","cvss":[{"version":"4.0","score":8.2,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","level":"high"}],"cwes":["CWE-201","CWE-823"],"updated_at":"2026-11-02T14:39:39.567266Z"}],"nvd":[{"id":"CVE-2026-32829","description":"lz4_flex is a pure Rust implementation of LZ4 compression/decompression. In versions 0.11.5 and below, and 0.12.0,  decompressing invalid LZ4 data can leak sensitive information from uninitialized memory or from previous decompression operations. The library fails to properly validate offset values during LZ4 \"match copy operations,\" allowing out-of-bounds reads from the output buffer. The block-based API functions (`decompress_into`, `decompress_into_with_dict`, and others when `safe-decode` is disabled) are affected, while all frame APIs are unaffected. The impact is potential exposure of sensitive data and secrets through crafted or malformed LZ4 input. This issue has been fixed in versions 0.11.6 and 0.12.1.","status":"published","published":"2026-03-20T01:15:56.277Z","modified":"2026-09-17T12:17:49.007Z","cvss":[{"version":"4.0","score":8.2,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high","assessor":"secondary"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"high","assessor":"primary"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"high","assessor":"secondary"}],"cwes":["CWE-201","CWE-823"],"updated_at":"2026-11-02T14:12:10.126802Z"}],"osv":[{"id":"CVE-2026-32829","title":"lz4_flex: Decompression can leak information from uninitialized memory or reused output buffer","description":"lz4_flex is a pure Rust implementation of LZ4 compression/decompression. In versions 0.11.5 and below, and 0.12.0,  decompressing invalid LZ4 data can leak sensitive information from uninitialized memory or from previous decompression operations. The library fails to properly validate offset values during LZ4 \"match copy operations,\" allowing out-of-bounds reads from the output buffer. The block-based API functions (`decompress_into`, `decompress_into_with_dict`, and others when `safe-decode` is disabled) are affected, while all frame APIs are unaffected. The impact is potential exposure of sensitive data and secrets through crafted or malformed LZ4 input. This issue has been fixed in versions 0.11.6 and 0.12.1.","status":"published","published":"2026-03-20T00:49:12.893Z","modified":"2026-10-28T02:30:31.929742261Z","cvss":[{"version":"4.0","score":8.2,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","level":"high"}],"cwes":["CWE-201","CWE-823"],"updated_at":"2026-11-02T15:45:01.548715Z"},{"id":"DEBIAN-CVE-2026-32829","description":"lz4_flex is a pure Rust implementation of LZ4 compression/decompression. In versions 0.11.5 and below, and 0.12.0,  decompressing invalid LZ4 data can leak sensitive information from uninitialized memory or from previous decompression operations. The library fails to properly validate offset values during LZ4 \"match copy operations,\" allowing out-of-bounds reads from the output buffer. The block-based API functions (`decompress_into`, `decompress_into_with_dict`, and others when `safe-decode` is disabled) are affected, while all frame APIs are unaffected. The impact is potential exposure of sensitive data and secrets through crafted or malformed LZ4 input. This issue has been fixed in versions 0.11.6 and 0.12.1.","status":"published","published":"2026-03-20T01:15:56.277Z","modified":"2026-10-01T03:03:10.389338538Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"high"}],"updated_at":"2026-11-02T15:45:54.232518Z"},{"id":"GHSA-vvp9-7p8x-rfvv","title":"lz4_flex's decompression can leak information from uninitialized memory or reused output buffer","description":"### Summary\nDecompressing invalid LZ4 data can leak data from uninitialized memory, or can leak content from previous decompression operations when reusing an output buffer.\n\n### Details\nThe 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.\nHowever, lz4_flex did not properly detect invalid and out-of-bounds _offset_ values properly, causing it to copy uninitialized data from the output buffer.\n\nOnly the block based API functions are affected: \n`lz4_flex::block::{decompress_into, decompress_into_with_dict}`\n\nWhen safe-decode is disabled _additionally_ these functions are affected\n`lz4_flex::block::{decompress, decompress_with_dict, decompress_size_prepended, decompress_size_prepended_with_dict}`\n\nAll `frame` APIs are _not_ affected.\n\nThere are two affected use cases:\n- decompressing LZ4 data with the `unsafe` implementation (`safe-decode` feature flag disabled, which is enabled by default):\ncan leak content of uninitialized memory as decompressed result\n- decompressing LZ4 data into a reused, user-supplied `output` buffer (affects the `safe-decode` feature as well):\ncan leak the previous contents of the output buffer as decompressed result\n\n### Impact\nLeakage of data from uninitialized memory or content from previous decompression operations, possibly revealing sensitive information and secrets.\n\n### Mitigation\nlz4_flex 0.12.1 and 0.11.6 fixes this issue without requiring changes in user code.\n\nIf you cannot upgrade, you can mitigate this vulnerability by zeroing the output buffer before calling `block::decompress_into` or  `block::decompress_into_with_dict` (only block based API is affected, frame API is not affected). Additionally the the `safe-decode` feature flag should be enabled.","status":"published","published":"2026-03-16T20:48:08Z","modified":"2026-09-10T03:50:41.31471076Z","cvss":[{"version":"4.0","score":8.2,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","level":"high"}],"cwes":["CWE-201","CWE-823"],"updated_at":"2026-11-02T15:46:57.694388Z"},{"id":"RUSTSEC-2026-0041","title":"Decompressing invalid data can leak information from uninitialized memory or reused output buffer","description":"Decompressing invalid LZ4 data with the block API can leak data from uninitialized memory,\nor leak content from previous decompression operations when reusing an output buffer.\n\nThe LZ4 block format defines a \"match copy operation\" which duplicates previously written\ndata or data from a user-supplied dict. The position of that data is defined by an _offset_.\n`lz4_flex` did not properly validate _offset_ values, causing it to copy data from outside\nthe initialized portion of the output buffer.\n\nTwo scenarios are affected:\n\n- Decompressing with the `unsafe` implementation (`safe-decode` feature flag disabled, which\n  is the default): can leak content of uninitialized memory as part of the decompressed result.\n- Decompressing into a reused, user-supplied output buffer (also affects `safe-decode`): can\n  leak the previous contents of the output buffer as part of the decompressed result.\n\nOnly the block-based APIs are affected. All frame APIs are unaffected.\n\nThe flaw was corrected in versions 0.11.6 and 0.12.1 by properly validating offset values\nduring decompression.\n\nIf upgrading is not possible, the issue can be mitigated by zeroing the output buffer before\neach call to the affected functions and enabling the `safe-decode` feature flag.","status":"published","published":"2026-03-17T12:00:00Z","modified":"2026-03-17T16:15:16.060046Z","cvss":[{"version":"4.0","score":8.2,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","level":"high"}],"updated_at":"2026-11-02T15:53:40.430679Z"},{"id":"UBUNTU-CVE-2026-32829","description":"lz4_flex is a pure Rust implementation of LZ4 compression/decompression. In versions 0.11.5 and below, and 0.12.0,  decompressing invalid LZ4 data can leak sensitive information from uninitialized memory or from previous decompression operations. The library fails to properly validate offset values during LZ4 \"match copy operations,\" allowing out-of-bounds reads from the output buffer. The block-based API functions (`decompress_into`, `decompress_into_with_dict`, and others when `safe-decode` is disabled) are affected, while all frame APIs are unaffected. The impact is potential exposure of sensitive data and secrets through crafted or malformed LZ4 input. This issue has been fixed in versions 0.11.6 and 0.12.1.","status":"published","published":"2026-03-20T01:15:00Z","modified":"2026-10-17T12:59:58.37019488Z","cvss":[{"version":"4.0","score":8.2,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","level":"high"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"high"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"high"}],"updated_at":"2026-11-02T16:56:16.036833Z"}]}}