CVE-2026-55246: Heap Overflow (CVSS 7.8)

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.

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CVSS v3.1 Score

7.8

HIGH

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Weakness Type (CWE)

CWE-122 CWE-122

CWE-787 Out-of-bounds Write

References

Other 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

Frequently Asked Questions

What is CVE-2026-55246? +

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. It has a CVSS v3.1 base score of 7.8 (HIGH).

How severe is CVE-2026-55246? +

CVE-2026-55246 has a CVSS v3.1 score of 7.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

How do I check if I'm vulnerable to CVE-2026-55246? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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