# CVE-2026-106971: CVE-2026-106971

Status: published. Published: 2026-10-28. Updated: 2026-11-03.

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

## Remediation

No remediation reported in collected sources

## Affected products and versions

- n/a / n/a: Version not specified (affected). Source: CNA: mitre

## Severity and prioritization

- CVSS 3.1: 7.5 (high); CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H; source: ADP: CISA-ADP

- CISA KEV: No listing in collected sources

- EPSS: 0.15% as of 2026-11-02; percentile 4.60%

- SSVC: exploitation poc; automatable yes; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-190, CWE-400

## Exploit evidence

- exploit: https://github.com/diptendukar/security-advisories/blob/main/CVE-2026-106971.md (ADP: CISA-ADP)

## References

- https://github.com/rybakit/msgpack.php (CNA: mitre)

- https://github.com/rybakit/msgpack.php/releases/tag/v0.11.0 (CNA: mitre)

- https://github.com/diptendukar/security-advisories/blob/main/CVE-2026-106971.md (CNA: mitre)

- https://github.com/diptendukar/security-advisories/blob/main/CVE-2026-106971.md (ADP: CISA-ADP; exploit)

## Provenance

- CNA: mitre: https://www.cve.org/CVERecord?id=CVE-2026-106971; retrieved 2026-11-03; source updated 2026-11-03

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-106971; retrieved 2026-11-03; source updated Not reported

Revision: b2b566644ef88592ec2268393a4f44a2c7205c24388930a24ca778e581676f9a

Canonical: https://y2.dev/cve/CVE-2026-106971

## Agent and API access

Public CVE pages, Markdown, and JSON are free to read without an account or API key.

- Public catalog: https://y2.dev/cve/index.json. Follow nextCursor with the same search, filters, sort, and limit (1–100). A null cursor marks the end.

- WebMCP: search_cve_disclosures, get_cve_disclosure, get_cve_page_markdown, get_y2_cve_access. Available in compatible browsers.

- Cyber API: https://api.y2.dev/api/v2/cyber/cves and https://api.y2.dev/api/v2/cyber/cves/{cveId}.

- Y2 Pro or Elite: create a workspace API key with the intel:cyber scope and send Authorization: Bearer <Y2_API_KEY>. Setup: https://y2.dev/docs/api/create-key.

- x402: Pay per request without an account or API key. Omit Authorization, read the HTTP 402 PAYMENT-REQUIRED challenge, validate its current requirements, and retry with PAYMENT-SIGNATURE through an authorized payment client. These browser tools never make payments. Guide: https://y2.dev/docs/api/x402.

- OpenAPI: https://y2.dev/api/openapi.yaml. Agent access metadata: https://y2.dev/cve/agent.json.

Collected public records only. Check source status for coverage and freshness.