Agent Development Kit (ADK): Missing Authentication for Critical Functionality
CVE-2026-4810 is a critical-severity missing authentication for critical functionality vulnerability in Agent Development Kit (ADK) from Google Cloud, with a CVSS 4.0 base score of 9.3 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 1.28.1, 2.0.0a2 as the first without the flaw, so updating Agent Development Kit (ADK) to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 2.2% chance of exploitation within 30 days, higher than 83% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update Agent Development Kit (ADK) to 1.28.1 or 2.0.0a2, whichever matches your release line, or a later version.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Google Cloud | Agent Development Kit (ADK) | 1.7.0 up to, but not including, 1.28.1; 2.0.0a1 up to, but not including, 2.0.0a2 | 1.28.1, 2.0.0a2 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Attack requirements
- NoneThe attack does not depend on a particular deployment or configuration.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Confidentiality (vulnerable system)
- HighSerious loss of confidentiality on the vulnerable system.
- Integrity (vulnerable system)
- HighSerious loss of integrity on the vulnerable system.
- Availability (vulnerable system)
- HighSerious loss of availability on the vulnerable system.
- Confidentiality (other systems)
- HighSerious loss of confidentiality on systems beyond the vulnerable one.
- Integrity (other systems)
- HighSerious loss of integrity on systems beyond the vulnerable one.
- Availability (other systems)
- HighSerious loss of availability on systems beyond the vulnerable one.
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Amber. Scored by CNA.
Official description
A Code Injection and Missing Authentication vulnerability in Google Agent Development Kit (ADK) versions 1.7.0 (and 2.0.0a1) through 1.28.1 (and 2.0.0a2) on Python (OSS), Cloud Run, and GKE allows an unauthenticated remote attacker to execute arbitrary code on the server hosting the ADK instance. This vulnerability was patched in versions 1.28.1 and 2.0.0a2. Customers need to redeploy the upgraded ADK to their production environments. In addition, if they are running ADK Web locally, they also need to upgrade their local instance.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Missing Authentication for Critical Functionality
The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.
How developers prevent this class of flaw
- For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, consider using libraries with authentication capabilities such as OpenSSL or the ESAPI Authenticator.
- When storing data in the cloud (e.g., S3 buckets, Azure blobs, Google Cloud Storage, etc.), use the provider's controls to require strong authentication for users who should be allowed to access the data.
More Missing Authentication for Critical Functionality vulnerabilities (CWE-306)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Other vulnerabilities in Agent Development Kit (ADK)
- 8.7 High severity
Recent Missing Authentication for Critical Functionality vulnerabilities
- 8.7 High severity
- 7.8 High severity
- 8.6 High severity
- 9.8 Critical severity
Marimo Remote Code Execution Exploited
- 8.1 High severity
- 9.1 Critical severity
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