High · CVSS 7.8CVE-2026-55246

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

Answer in brief

CVE-2026-55246 records a High severity (CVSS 7.8) vulnerability in bincookie: Heap buffer overflow via unvalidated `num_pages` when parsing a `.binarycookies` file. The current sources do not mark it as known exploited. The current feed maps Tatsh/bincookie (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Oct 15, 2026Updated Oct 15, 2026Source checked Oct 15, 2026First seen by HOL Oct 15, 2026Material review Oct 15, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 7.8
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

CVSS is 7.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Tatsh/bincookie (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Tatsh/bincookiegeneric	<0.1.9	0.1.9

Recommended response

Check inventory. Check lockfiles and deployed manifests for Tatsh/bincookie.
Review the reported fix. Update Tatsh/bincookie to 0.1.9 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Oct 15, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Oct 15, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Oct 15, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.