Integer overflow in rybakit/msgpack BufferUnpacker enables DoS
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA. Impact type from CWE-190 and the CVSS impact.
Summary
rybakit/msgpack versions prior to 0.11.0 are affected. An integer overflow in the MessagePack\BufferUnpacker component (CWE-190) lets crafted MessagePack input cause a denial of service when the application runs on 32-bit PHP. An unauthenticated remote attacker can send such input over the network without user interaction.
Written with Claude Haiku 5.5 from the sources below · 2026-11-03
Description from the CNA
An integer overflow in the MessagePack\BufferUnpacker component of rybakit/msgpack versions prior to 0.11.0 allows attackers to cause a denial of service via crafted MessagePack input when the application runs on 32-bit PHP
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
Remediation
Upgrade rybakit/msgpack to version 0.11.0 or later.
Written with Claude Haiku 5.5 from the sources below · 2026-11-03
Timeline
- 2026-10-28 Threatist record created from CVE-2026-106971
- 2026-10-28 Alias added: GHSA-w6qp-mj4x-9485
- 2026-10-29 Title updated · CNA
- 2026-11-03 CVSS score added · CISA ADP
- 2026-11-03 Weakness changed · CISA ADP
- 2026-11-03 CISA SSVC decision points changed
- 2026-11-03 Priority changed: LOW → HIGH
References
Sources
- CVE-2026-106971 · CVE Program
- CVE-2026-106971 · NVD
- FIRST EPSS
- GHSA-w6qp-mj4x-9485 · GitHub Advisory Database · CC BY 4.0
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