{"id":"AZL-81324","summary":"CVE-2026-33416 affecting package gdal 3.6.3-2","details":"LIBPNG is a reference library for use in applications that read, create, and manipulate PNG (Portable Network Graphics) raster image files. In versions 1.2.1 through 1.6.55, `png_set_tRNS` and `png_set_PLTE` each alias a heap-allocated buffer between `png_struct` and `png_info`, sharing a single allocation across two structs with independent lifetimes. The `trans_alpha` aliasing has been present since at least libpng 1.0, and the `palette` aliasing since at least 1.2.1. Both affect all prior release lines `png_set_tRNS` sets `png_ptr-\u003etrans_alpha = info_ptr-\u003etrans_alpha` (256-byte buffer) and `png_set_PLTE` sets `info_ptr-\u003epalette = png_ptr-\u003epalette` (768-byte buffer). In both cases, calling `png_free_data` (with `PNG_FREE_TRNS` or `PNG_FREE_PLTE`) frees the buffer through `info_ptr` while the corresponding `png_ptr` pointer remains dangling. Subsequent row-transform functions dereference and, in some code paths, write to the freed memory. A second call to `png_set_tRNS` or `png_set_PLTE` has the same effect, because both functions call `png_free_data` internally before reallocating the `info_ptr` buffer. Version 1.6.56 fixes the issue.","modified":"2026-09-02T05:29:58Z","published":"2026-03-26T17:16:38Z","upstream":["CVE-2026-33416"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-33416"}],"affected":[{"package":{"name":"gdal","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/gdal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"3.6.3-2"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-81324.json"}}],"schema_version":"1.9.0"}