CVE-2021-26557

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-10-07 · updated 2026-06-17
Weakness: CWE-426

Description

When Octopus Tentacle is installed using a custom folder location, folder ACLs are not set correctly and could lead to an unprivileged user using DLL side-loading to gain privileged access.

Affected products

Octopus Deploy Octopus Tentacle: from 3.15.4 before 6.0.489 — fixed in 6.0.489

How to fix

Upgrade to a fixed version: Octopus Deploy Octopus Tentacle 6.0.489. Check the vendor advisory for mitigations.

References

https://advisories.octopus.com/adv/2021-02---Local-privilege-escalation-in-Octopus-Tentacle-%28CVE-2021-26557%29.1732870264.html
https://advisories.octopus.com/adv/2021-02---Local-privilege-escalation-in-Octopus-Tentacle-%28CVE-2021-26557%29.1732870264.html

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