Heap buffer overflow in bincookie parsing of binarycookies files
Key facts
- Attack vector
- Local
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-122 and the CVSS impact.
Summary
Tatsh bincookie versions before 0.1.9 are affected. The header-only binarycookies parser trusts the file-controlled num_pages field as a loop bound in bincookie_init_file(), so a crafted file makes the loop write past a heap allocation (CWE-122). An application that parses an attacker-supplied binarycookies file may crash or suffer heap corruption that can potentially enable code execution. The source notes a proof-of-concept exists in its SSVC data but no public exploit is linked in the references.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
Description from the CNA
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
Update Tatsh bincookie to version 0.1.9, which fixes the issue.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
- Fix · CNA bincookie (Tatsh) Fixed in 0.1.9
Vendor assessments
Timeline
- 2026-10-16 Threatist record created from CVE-2026-55246
- 2026-11-06 Affected versions changed · Red Hat
- 2026-11-06 CVSS score added · Red Hat
References
Sources
- CVE-2026-55246 · CVE Program
- CVE-2026-55246 · NVD
- FIRST EPSS
- CVE-2026-55246 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences