VulnerabilityPublished 6 Jul 2026

CVE-2026-55432: V2 · Coder's sub-agent app registration bypasses template port-sharing policy enforcement

Affects github.com/coder/coder/v2Source GCVE Database

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Not known to be exploited · CVSS 5.4 Medium : upgrade to 2.34.2 when convenient.

Data as of 29 Oct 2026, 19:04 UTC

CVSS 3.1 base score

5.4Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.3% chance of exploitation in 30 days – higher than 24% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 2.34.2, 2.33.8, 2.32.7 +1

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: Low
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 6 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
Gogithub.com/coder/coder/v2	Affected >=2.34.0 <2.34.2	Fixed in 2.34.2
Gogithub.com/coder/coder/v2	Affected >=2.33.0 <2.33.8	Fixed in 2.33.8
Gogithub.com/coder/coder/v2	Affected >=2.30.0 <2.32.7	Fixed in 2.32.7
Gogithub.com/coder/coder/v2	Affected <2.29.17	Fixed in 2.29.17

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Apply the official patches available in versions 2.34.2, 2.33.8, 2.32.7, or 2.29.17 to ensure the sub-agent app sharing level is properly clamped to the template's MaxPortSharingLevel. If immediate patching is not possible, disable wildcard app hostnames (CODER_WILDCARD_ACCESS_URL) to block subdomain-based app routing and prevent exposure via wildcard domains.

Description

### Summary The `CreateSubAgent` RPC did not validate a requested app sharing level against the template's `MaxPortSharingLevel` before persisting workspace apps, letting a workspace owner exceed the administrator's configured maximum. > **Note:** Exploitation requires the ability to register sub-agent apps in a workspace the attacker controls. ### Impact A workspace owner with an agent token could register a sub-agent app as `PUBLIC` even when the template's `MaxPortSharingLevel` was `owner`, exposing the app to unauthenticated users via the wildcard app domain. This affected only deployments using Enterprise port-sharing policy and wildcard app hostnames and required an authenticated workspace owner with an agent token. ### Patches The fix clamps the sub-agent app sharing level to the template's `MaxPortSharingLevel`. 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 Disable wildcard app hostnames (`CODER_WILDCARD_ACCESS_URL`) to block subdomain-based app routing. ### Resources - Fix: #26061 ### Credits Coder would like to thank Anthropic's Security Team (ANT-2026-22452) for independently disclosing this issue!

Impact

An authenticated workspace owner with an agent token can bypass the configured maximum port-sharing level by registering a sub-agent app with a higher sharing level than allowed by the template. This can expose the app to unauthenticated users via wildcard app domains, potentially leaking information or access beyond intended limits. The impact is limited to environments using Enterprise port-sharing policies with wildcard app hostnames and requires authenticated access with sufficient privileges. There is no indication of denial of service or integrity impact.

Summary

The CreateSubAgent RPC in github.com/coder/coder/v2 did not enforce the template's MaxPortSharingLevel when registering sub-agent apps, allowing a workspace owner with an agent token to register a sub-agent app with a sharing level exceeding the administrator-configured maximum. This flaw permits setting the sharing level to PUBLIC even if the template restricts it to owner-only, exposing the app to unauthenticated users via wildcard app hostnames. Exploitation requires authenticated access as a workspace owner with an agent token and affects deployments using Enterprise port-sharing policies with wildcard app hostnames. The issue is tracked as CVE-2026-55432 and CWE-862 (Missing Authorization). The vendor released official patches in versions 2.34.2, 2.33.8, 2.32.7, and 2.29.17, which clamp the sub-agent app sharing level to the template's MaxPortSharingLevel. A workaround is to disable wildcard app hostnames (CODER_WILDCARD_ACCESS_URL).

CWE-862Missing Authorization (opens in a new tab)
Class weaknessLikelihood of exploit: HighCWE Top 25 (2025): #4OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
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) to enforce the roles at the appropriate boundaries.
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.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
OWASP Cheat Sheets
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V8.3.8 (opens in a new tab)
V13.4.2 (opens in a new tab)
V7.2.2 (opens in a new tab)
Attack patterns
Exploitation of Thunderbolt Protection Flaws (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 6 Jul 2026, 23:12 UTC

WeaknessesCWE-862

Technical details

References

Community reviews

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