Threat Intelligence / CVE / CVE-2026-82533

CVE-2026-82533 — DeepSeek Harness

CVSS v3.1 9.6 (CRITICAL) · CVSS v4.0 9.4 · EPSS 0.4% (higher than 35.0% of all scored CVEs) · Priority 6.2/10 · Published 2026-09-08

As of 2026-09-08, CVE-2026-82533 is a CRITICAL-severity vulnerability in DeepSeek Harness, CVSS v3.1 9.6, EPSS 0.4% (35.0th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-82533, most recently “DeepSeek Harness Authentication Bypass Lets Sandboxed AI Agents Escape via Single Command (CVE-2026-82533)”.

Last updated: 2026-09-08

What is CVE-2026-82533?

DeepSeek Harness before 0.1.2-alpha.1 contains an authentication bypass vulnerability in its local HTTP control-plane API that allows attackers to gain full agent control by supplying a spoofed Host header, as the server validates only the client-supplied Host header value rather than the actual TCP connection origin. Attackers can exploit this flaw to invoke privileged commands such as commands/execute with danger-full-access permissions, escalate session approval policies to unconfined execution, and retrieve all stored conversations without any credential or API key.

The record classifies CVE-2026-82533 under weakness class CWE-807. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs a user to take an action first, and has high impact on confidentiality, integrity, availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 4 days ago.

Severity and exploitation probability

CVSS v3.1 base score: 9.6 — CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
CVSS v4.0 base score: 9.4
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
EPSS (FIRST): 0.4% probability of exploitation in the next 30 days, higher than 35.0% of all scored CVEs
CISA KEV: Not listed in the CISA Known Exploited Vulnerabilities catalog
Threadlinqs priority: 6.2/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
Published: 2026-09-08

Is CVE-2026-82533 being exploited?

No public exploitation evidence for CVE-2026-82533 is recorded in the sources Threadlinqs tracks — CISA KEV, Exploit-DB, public proof-of-concept repositories and ProjectDiscovery Nuclei — as of 2026-09-08. That is an absence of evidence in those feeds, not a guarantee that the vulnerability is unexploited.

Affected products and versions

DeepSeek: Harness

How to fix CVE-2026-82533

No vendor patch reference has been recorded for CVE-2026-82533 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

Threat activity tracking CVE-2026-82533

1 tracked threat in the Threadlinqs corpus references CVE-2026-82533, either in the campaign’s CVE list or as an indicator on the campaign record.

DeepSeek Harness Authentication Bypass Lets Sandboxed AI Agents Escape via Single Command (CVE-2026-82533) — CRITICAL · 2026-09-09

Sources

Enriched from CVE.org, NVD, FIRST EPSS, GitHub Security Advisories. Last verified by Threadlinqs on 2026-09-09. This product uses the NVD API but is not endorsed or certified by the NVD.

Vendor advisory and patch

Third-party advisory

vulncheck.com — third party advisory

Full detection coverage & IOCs for threats exploiting CVE-2026-82533 are available via the Threadlinqs MCP server (Purple tier). View plans →

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