CVE-2026-55433: Anthropic Python — MEDIUM

### Summary The devcontainer recreate endpoint relied on route middleware that checked only `ActionRead` on the workspace and, unlike the sibling delete endpoint, performed no `ActionUpdate` check before triggering the destructive rebuild. > **Note:** Exploitation requires an existing...

Full CISO analysis pending enrichment.

What systems are affected?

Package	Ecosystem	Vulnerable Range	Patched
Anthropic Python	go	>= 2.34.0, < 2.34.2	`2.34.2`
3.7K 5.4K dependents Pushed 4d ago 95% patched ~3d to patch Full package profile →

Do you use Anthropic Python? You're affected.

How severe is it?

CVSS 3.1

5.4 / 10

EPSS

N/A

Exploitation Status

No known exploitation

Sophistication

N/A

What is the attack surface?

AV Network

AC Low

PR Low

UI None

S Unchanged

C None

I Low

A Low

What should I do?

Patch available

Update Anthropic Python to version 2.34.2

Which compliance frameworks are affected?

Compliance analysis pending. Sign in for full compliance mapping when available.

Frequently Asked Questions

What is CVE-2026-55433?

### Summary The devcontainer recreate endpoint relied on route middleware that checked only `ActionRead` on the workspace and, unlike the sibling delete endpoint, performed no `ActionUpdate` check before triggering the destructive rebuild. > **Note:** Exploitation requires an existing low-privilege role with access to the target workspace. ### Impact Any authenticated principal with read-only workspace access, such as a Template Admin or Org Template Admin, could recreate a devcontainer, destroying uncommitted in-container state and, if called repeatedly, denying service. This is an authorization bypass leading to data loss and denial of service. ### Patches The fix adds an explicit `ActionUpdate` authorization check before the agent is dialed like the delete endpoint. The fix was backported to all supported release lines: | Release line | Patched version | |---|---| | 2.34 | [v2.34.2](https://github.com/coder/coder/releases/tag/v2.34.2) | | 2.33 | [v2.33.8](https://github.com/coder/coder/releases/tag/v2.33.8) | | 2.32 | [v2.32.7](https://github.com/coder/coder/releases/tag/v2.32.7) | | 2.29 (ESR) | [v2.29.17](https://github.com/coder/coder/releases/tag/v2.29.17) | ### Workarounds None. ### Resources - Fix: #25812 ### Credits Coder would like to thank Anthropic's Security Team (ANT-2026-22454) for independently disclosing this issue!

Is CVE-2026-55433 actively exploited?

No confirmed active exploitation of CVE-2026-55433 has been reported, but organizations should still patch proactively.

How to fix CVE-2026-55433?

Update to patched version: Anthropic Python 2.34.2.

What is the CVSS score for CVE-2026-55433?

CVE-2026-55433 has a CVSS v3.1 base score of 5.4 (MEDIUM).

What are the technical details?

Original Advisory

### Summary The devcontainer recreate endpoint relied on route middleware that checked only `ActionRead` on the workspace and, unlike the sibling delete endpoint, performed no `ActionUpdate` check before triggering the destructive rebuild. > **Note:** Exploitation requires an existing low-privilege role with access to the target workspace. ### Impact Any authenticated principal with read-only workspace access, such as a Template Admin or Org Template Admin, could recreate a devcontainer, destroying uncommitted in-container state and, if called repeatedly, denying service. This is an authorization bypass leading to data loss and denial of service. ### Patches The fix adds an explicit `ActionUpdate` authorization check before the agent is dialed like the delete endpoint. The fix was backported to all supported release lines: | Release line | Patched version | |---|---| | 2.34 | [v2.34.2](https://github.com/coder/coder/releases/tag/v2.34.2) | | 2.33 | [v2.33.8](https://github.com/coder/coder/releases/tag/v2.33.8) | | 2.32 | [v2.32.7](https://github.com/coder/coder/releases/tag/v2.32.7) | | 2.29 (ESR) | [v2.29.17](https://github.com/coder/coder/releases/tag/v2.29.17) | ### Workarounds None. ### Resources - Fix: #25812 ### Credits Coder would like to thank Anthropic's Security Team (ANT-2026-22454) for independently disclosing this issue!

Weaknesses (CWE)

CWE-862 Missing Authorization Primary

CWE-862 — Missing Authorization: The product does not perform an authorization check when an actor attempts to access a resource or perform an action.

[Architecture and Design] Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) [REF-229] to enforce the roles at the appropriate boundaries. Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.
[Architecture and Design] Ensure that access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied to more generic resources such as files, connections, processes, memory, and database records. For example, a database may restrict access for medical records to a specific database user, but each record might only be intended to be accessible to the patient and the patient's doctor [REF-7].

Source: MITRE CWE corpus.