Bug 2562453 (CVE-2026-58496)

Summary: CVE-2026-58496 thorvg: thorvg: Information disclosure via undersized font data
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Priority: medium    
Version: unspecifiedKeywords: Security
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OS: Linux   
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A flaw was found in ThorVG. The vector graphics engine's font loader does not verify that an input buffer contains the minimum required data before attempting to inspect font headers. An attacker could exploit this flaw by enticing an application to load a specially crafted, undersized font directly into memory. Successful exploitation can result in information disclosure by reading adjacent memory, or cause an application crash leading to a Denial of Service (DoS).
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Description OSIDB Bzimport 2026-10-27 22:31:57 UTC 
Thor Vector Graphics (ThorVG) is a production-ready vector graphics engine. Prior to 1.0.7, the `SFNT/TTF` font loader's `SfntLoader::gen` function in `tvgSfntLoader.cpp` reads `data[0] through data[3]` to identify the font type without first checking that the input buffer contains at least four bytes. Loading an undersized font directly from memory through public APIs such as `tvg::Text::load` causes an out-of-bounds read. Loading through a file path using `mmap` can mask the read because of page alignment; the memory-loading API directly exposes it. Depending on memory layout, a malformed short font may crash the consuming application or disclose adjacent heap memory. This issue is fixed in version 1.0.7.