Apache APISIX: Reliance on Untrusted Inputs in a Security Decision
CVE-2026-63041 is a high-severity reliance on untrusted inputs in a security decision vulnerability in Apache APISIX from Apache, with a CVSS 3.1 base score of 8.8 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. Affected Apache APISIX versions: 3.11.0 through 3.17.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.68% chance of exploitation within 30 days, higher than 53% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Apisix to 3.18.0 or a later version.
- Read the advisory on lists.apache.org for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Apache | Apache APISIX | 3.11.0 through 3.17.0 | Not stated |
| Apache | Apisix | 3.11.0 up to, but not including, 3.18.0 | 3.18.0 |
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
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 5.3 | Medium | CNA (apache.org) |
| CVSS 3.1 | 8.8 | High | NVD |
Official description
Reliance on Untrusted Inputs in a Security Decision vulnerability in Apache APISIX. This vulnerability allows an attacker to escalate privilege or perform an authorization bypass by sending certain values that the attach-consumer-label plugin does not sanitise correctly. This issue affects Apache APISIX: from 3.11.0 through 3.17.0. Users are recommended to upgrade to version 3.18.0, which fixes the issue.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Reliance on Untrusted Inputs in a Security Decision
The product uses a protection mechanism that relies on the existence or values of an input, but the input can be modified by an untrusted actor in a way that bypasses the protection mechanism.
How developers prevent this class of flaw
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. With a stateless protocol such as HTTP, use a framework that maintains the state for you. Examples include ASP.NET View State and the OWASP ESAPI Session Management feature. Be careful of language features that provide state support, since these might be provided as a convenience to the programmer and may not be considering security.
- 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.
- When using PHP, configure the application so that it does not use register_globals. During implementation, develop the application so that it does not rely on this feature, but be wary of implementing a register_globals emulation that is subject to weaknesses such as CWE-95, CWE-621, and similar issues.
More Reliance on Untrusted Inputs in a Security Decision vulnerabilities (CWE-807)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Third-party and government advisories
- openwall.com/lists/oss-security/2026/08/26/11Mailing List, Third Party Advisory
Other vulnerabilities in Apache APISIX
- 7.0 High severity
- 7.8 High severity
- 8.2 High severity
- 8.1 High severity
- 7.5 High severity
- 7.5 High severity
Recent Reliance on Untrusted Inputs in a Security Decision vulnerabilities
- 8.1 High severity
- 8.5 High severity
- 9.8 Critical severity
- 8.1 High severity
- 7.3 High severity
- 7.3 High severity
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