{"id":"CVE-2026-52834","aliases":["GHSA-5pmv-rx8r-wmv5","RUSTSEC-2026-0151"],"url":"https://o3.security/vulnerability/CVE-2026-52834","summary":"jxl-oxide: Out-of-bounds writes due to integer overflow in jxl-grid on 32-bit platforms","details":"### Summary\n\nOn 32-bit platforms, decoding a crafted image may lead to out-of-bounds writes due to integer overflow in length calculation.\n\n### Details & PoC\n\nThe test listed below fail under miri with command `cargo +nightly miri test --release -p jxl-grid`\n\nOr you can use Address Sanitizer, which ignores Rust-specific UB like aliasing but still flags out-of-bounds accesses:\n\n`RUSTFLAGS=-Zsanitizer=address cargo +nightly test -Zbuild-std -p jxl-grid --release --target x86_64-unknown-linux-gnu`\n\nThe following tests should be appended to `crates/jxl-grid/src/test/subgrids.rs`:\n\n```rust\nmod miri_ub {\n    use super::*;\n\n    // `AlignedGrid::with_alloc_tracker` computes `width * height` unchecked. In release, overflow\n    // can create a tiny backing buffer for huge logical dimensions.\n    #[test]\n    fn aligned_grid_dimension_product_overflows() {\n        let width = usize::MAX / 2 + 1;\n        let mut grid = AlignedGrid::<u8>::with_alloc_tracker(width, 2, None).unwrap();\n        let mut subgrid = grid.as_subgrid_mut();\n        *subgrid.get_mut(0, 1) = 1;\n        std::hint::black_box(grid);\n    }\n}\n```\n\nThis issue can be reachable through decoding a crafted image in two ways:\n\n1. **Huge actual frame**\n   A frame such as `65536 x 65536` passes the current frame area limit (`2^32 <= 2^40`) but overflows `usize` element count on 32-bit. Rendering then allocates too-small `AlignedGrid`s in modular/VarDCT/filter paths and later writes through mutable subgrids.\n\n2. **Huge canvas plus tiny cropped frame**\n   This is the more practical “small payload, huge logical output” case. A bitstream-controlled frame crop can be tiny, but if the canvas/default requested region is huge, composition can allocate an output grid sized to the canvas/ROI at crates/jxl-render/src/blend.rs. That is bitstream frame cropping, not API crop. With a 32-bit target and a full requested image region whose area overflows, this can happen through ordinary `render_frame()`.\n\n### Impact\n\nOn 32-bit platforms this can cause out-of-bounds writes with attacker-controlled data when decoding a crafted JPEG XL image. This could allow arbitrary code execution.","published":"2026-08-19T14:55:32.138Z","modified":"2026-10-21T02:53:49.677947487Z","cvss":{"score":7.3,"severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:H"},"epss":{"score":0.0013,"percentile":0.03034,"asOf":"2026-09-16"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"crates.io","name":"jxl-grid","fixedVersion":"0.6.2"}],"fix":{"url":"https://github.com/tirr-c/jxl-oxide/commit/3986dadd3926a95656a642e74a0702d52f5c92e2","label":"tirr-c/jxl-oxide@3986dad"},"references":[{"type":"WEB","url":"https://github.com/tirr-c/jxl-oxide/releases/tag/0.12.6"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/52xxx/CVE-2026-52834.json"},{"type":"ADVISORY","url":"https://github.com/tirr-c/jxl-oxide/security/advisories/GHSA-5pmv-rx8r-wmv5"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-52834"},{"type":"ADVISORY","url":"https://rustsec.org/advisories/RUSTSEC-2026-0151.html"},{"type":"FIX","url":"https://github.com/tirr-c/jxl-oxide/commit/3986dadd3926a95656a642e74a0702d52f5c92e2"},{"type":"PACKAGE","url":"https://github.com/tirr-c/jxl-oxide"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-10-21T02:53:49.677947487Z"}}