strands-agents-tools: Authorization Bypass Through User-Controlled Key
CVE-2026-19111 is a high-severity authorization bypass through user-controlled key vulnerability in strands-agents-tools from AWS, with a CVSS 3.1 base score of 8.1 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. The record lists version 0.8.3 as the first without the flaw, so updating strands-agents-tools to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.52% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update strands-agents-tools to 0.8.3 or a later version.
- Read the advisory on aws.amazon.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| AWS | strands-agents-tools | before 0.8.3 | 0.8.3 |
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.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N. Scored by CNA.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 8.6 | High | CNA |
| CVSS 3.1 | 8.1 | High | CNA |
Official description
Insecure direct object reference in the mongodb_memory, elasticsearch_memory, and mem0_memory tools in Amazon Strands Agents Tools before 0.8.3 might allow remote authenticated users to access, modify, or delete memories belonging to other tenants by influencing the LLM to emit tool calls with a forged namespace parameter. To remediate this issue, users should upgrade to version 0.8.3.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Authorization Bypass Through User-Controlled Key
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.
How developers prevent this class of flaw
- For each and every data access, ensure that the user has sufficient privilege to access the record that is being requested.
- 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.
- 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.
More Authorization Bypass Through User-Controlled Key vulnerabilities (CWE-639)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Other references
Other vulnerabilities in strands-agents-tools
- 7.4 High severity
Recent Authorization Bypass Through User-Controlled Key vulnerabilities
- 9.9 Critical severity
- 8.5 High severity
- 7.5 High severity
- 8.8 High severity
- 7.1 High severity
- 8.3 High severity
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