VulnerabilityPublished 6 Jul 2026

CVE-2026-55429: V2 · Coder's workspace app upsert allows cross-workspace agent rebinding via user-controlled app ID

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

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Not known to be exploited · CVSS 8.7 High : upgrade to 2.34.2 soon.

Data as of 30 Oct 2026, 06:59 UTC

CVSS 3.1 base score

8.7High

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

EPSS: 0.5% chance of exploitation in 30 days – higher than 43% 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:H/UI:N/S:C/C:H/I:H/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: High
User Interaction: None
Scope: Changed
Confidentiality: High
Integrity: High
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: High: The attacker is authorized with (i.e., requires) privileges that provide significant (e.g., administrative) control over the vulnerable component that could affect component-wide settings and files.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to 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

A fix is available and has been backported to all supported release lines: versions 2.34.2, 2.33.8, 2.32.7, and 2.29.17. Upgrading to these versions or later is required to mitigate this vulnerability. No workarounds exist. Users should apply the official patches promptly.

Description

### Summary `UpsertWorkspaceApp` overwrites an existing app's `agent_id` on a primary-key conflict and `insertAgentApp` accepts the app ID from the provisioner's `CompleteJob` payload without verifying it belongs to the workspace being built. `CompleteJob` runs under `dbauthz.AsProvisionerd` so the authorization layer does not block the cross-workspace upsert. > **Note:** Exploitation requires elevated access as a template author or external provisioner operator. ### Impact A user with template authorship or external provisioner access can submit a `CompleteJob` payload with a known victim app UUID and an attacker-controlled agent ID. On completion of the attacker's build the victim's app row is rebound to the attacker's agent so later app traffic such as IDE and terminal sessions is proxied to the attacker's workspace. App UUIDs are discoverable through the public API. ### Patches The fix verifies that any existing `workspace_apps` row matching the supplied ID belongs to the workspace being built and rejects cross-workspace agent reassignment. 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. Upgrading is required. ### Resources - Fix: #26103 ### Credits Coder would like to thank Anthropic's Security Team (ANT-2026-22441) for independently disclosing this issue!

Impact

An attacker with elevated privileges (template author or external provisioner operator) can rebind a victim app's agent to their own agent by exploiting the upsert process, enabling interception and proxying of the victim's app traffic, including IDE and terminal sessions. This compromises confidentiality and integrity of the victim's workspace app communications. The vulnerability requires elevated privileges and knowledge of victim app UUIDs, which are discoverable via the public API.

CWE-639Authorization Bypass Through User-Controlled Key (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #24OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.
Architecture and Design
For each and every data access, ensure that the user has sufficient privilege to access the record that is being requested.
Architecture and Design · Implementation
Make sure that the key that is used in the lookup of a specific user's record is not controllable externally by the user or that any tampering can be detected.
Architecture and Design
Use encryption in order to make it more difficult to guess other legitimate values of the key or associate a digital signature with the key so that the server can verify that there has been no tampering.
OWASP Cheat Sheets
Access Control (opens in a new tab)
Authorization Testing Automation (opens in a new tab)
Cross-Site Request Forgery Prevention (opens in a new tab)
Insecure Direct Object Reference Prevention (opens in a new tab)
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V4.1.2 (opens in a new tab)
V4.2.1 (opens in a new tab)
V8.3.8 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 6 Jul 2026, 23:13 UTC

WeaknessesCWE-639

Technical details

References

Community reviews

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