VulnerabilityPublished 24 Mar 2026

CVE-2026-33768: withastro astro · Confused Deputy

Affects withastro astroSource CVE Database V5

Compare

Not known to be exploited · CVSS 6.5 Medium : upgrade to 10.0.2 when convenient.

Data as of 30 Oct 2026, 11:52 UTC

CVSS 3.1 base score

6.5Medium

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

EPSS: 0.3% chance of exploitation in 30 days – higher than 27% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 10.0.2

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
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: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
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 24 Mar 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 30 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 withastro astro to 10.0.2.

Affected software

Product	Affected	Fixed in
withastroastro	Affected <10.0.2	Fixed in 10.0.2

AI-suggested

To mitigate this vulnerability, organizations should upgrade all Astro framework instances to version 10.0.2 or later, where the issue is patched. Deployments on Vercel should enable Edge Middleware to enforce path restrictions at the edge, preventing unauthorized path rewrites. Review and strengthen access control mechanisms beyond relying solely on path-based firewall rules, incorporating authentication and authorization checks within application logic. Implement strict validation and sanitization of HTTP headers and query parameters, especially those influencing routing or internal path resolution. Monitor logs for suspicious requests containing x-astro-path headers or x_astro_path query parameters targeting sensitive endpoints. Consider deploying Web Application Firewalls (WAFs) with custom rules to detect and block requests attempting to exploit this path rewriting behavior. Conduct security testing and code reviews to ensure no other unintended proxies or path overrides exist. Finally, educate development and operations teams about the risks of relying on client-controlled headers for internal routing decisions.

Description

CVE-2026-33768 is a medium severity vulnerability in the Astro web framework versions prior to 10.0.2. It involves an unintended proxy or 'confused deputy' issue where the @astrojs/vercel serverless entrypoint reads the x-astro-path header and x_astro_path query parameter to rewrite internal request paths without any authentication. This allows attackers to bypass platform-level path restrictions on Vercel deployments lacking Edge Middleware, enabling unauthorized access to restricted paths such as /admin. The vulnerability affects all HTTP methods, including POST, PUT, and DELETE, preserving the original method and body, which can lead to unauthorized actions. Firewall rules blocking sensitive paths are ineffective against requests exploiting this flaw. The issue has been patched in Astro version 10.0.2.

Impact

The vulnerability allows attackers to bypass platform-level path restrictions on Vercel deployments using Astro versions prior to 10.0.2, potentially gaining unauthorized access to sensitive internal endpoints such as administrative interfaces. Because the rewrite preserves HTTP methods and request bodies, attackers can perform unauthorized state-changing operations (e.g., deleting users, modifying data) by crafting requests that appear to target allowed paths but are internally redirected to restricted ones. This undermines the confidentiality and integrity of affected applications and can lead to privilege escalation or data compromise. Organizations relying on Astro for serverless deployments on Vercel without Edge Middleware are at risk, especially if they use path-based firewall rules for access control. The lack of authentication on the path rewrite mechanism means exploitation is straightforward and requires no credentials or user interaction. While availability is not directly impacted, the unauthorized actions could indirectly disrupt services or cause data loss. The medium severity rating reflects the significant but not catastrophic impact, assuming mitigations like Edge Middleware or updated Astro versions are not in place.

CWE-441Unintended Proxy or Intermediary (Confused Deputy) (opens in a new tab)
Class weaknessOWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product receives a request, message, or directive from an upstream component, but the product does not sufficiently preserve the original source of the request before forwarding the request to an external actor that is outside of the product's control sphere.
Architecture and Design
Enforce the use of strong mutual authentication mechanism between the two parties.
Architecture and Design
Whenever a product is an intermediary or proxy for transactions between two other components, the proxy core should not drop the identity of the initiator of the transaction. The immutability of the identity of the initiator must be maintained and should be forwarded all the way to the target.
OWASP Cheat Sheets
Authorization (opens in a new tab)
Attack patterns
XML Routing Detour Attacks (opens in a new tab)
Transparent Proxy Abuse (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
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).

References

Community reviews

Loading reviews…

Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 31 Mar 2026, 20:36 UTC

WeaknessesCWE-441, CWE-862

Technical details

References

Community reviews

Related threats