Copilot Cowork Elevation of Privilege Vulnerability

published 2026-08-06 3 mo ago modified 2026-10-30 9 d ago also EUVD-2026-54314

cvss: 9.3; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.7%; EPSS 0.7% chance of exploitation in 30 days, percentile 54%
public exploits: 0; none known

Improper authorization in Copilot Cowork allows an unauthorized attacker to elevate privileges over a network.

Patch / fix

links 1

msrc.microsoft.com/update-guide/vulnerability/CVE-2026-59118 advisory

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: total
Assessed: 3 mo ago (2026-08-06)

Exploit prediction

0.72% chance of exploitation in the next 30 days, higher than 54% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	9.3	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N/E:U/RL:O/RC:C
CNA	3.1	9.3	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N

Affected products

Microsoft Copilot Cowork

Classification

Weakness

CWE-285 Improper Authorization

References

msrc.microsoft.com /update-guide/vulnerability/CVE-2026-59118
vendor-advisory, patch

Sources

CVE List CVE-2026-59118
NVD CVE-2026-59118

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary