What’s Vulnerable › Vulnerabilities

CVE-2026-55246: bincookie: Heap buffer overflow via unvalidated `num_pages` when parsing a `.binarycookies` file

• Severity: high (CVSS 7.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-15 · updated 2026-10-16
• Weakness: CWE-122

Description

bincookie is a header-only binarycookies parser. Prior to 0.1.9, bincookie_init_file() in bincookie.h allocates a buffer using the actual .binarycookies file length but trusts the file-controlled num_pages field as the loop bound for byte-swapping page_sizes entries. A crafted file can make the loop read and write beyond the heap allocation, and related unvalidated page sizes and cookie_offsets can drive additional out-of-bounds accesses in page and cookie iteration. Applications that parse an attacker-supplied binarycookies file may crash or suffer heap corruption that can potentially enable code execution. This issue is fixed in version 0.1.9.

Affected products

• Tatsh bincookie: before 0.1.9

References

• https://github.com/Tatsh/bincookie/commit/bc1433c1ee4d0284750ff85c8437f1b8df91ab3b
• https://github.com/Tatsh/bincookie/releases/tag/v0.1.9
• https://github.com/Tatsh/bincookie/security/advisories/GHSA-22pc-xxw4-q849
• https://github.com/Tatsh/bincookie/security/advisories/GHSA-22pc-xxw4-q849

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