grav-plugin-api: URL Redirection to Untrusted Site
CVE-2026-61451 is a critical-severity URL redirection to untrusted site vulnerability in grav-plugin-api from Grav, with a CVSS 3.1 base score of 9.6 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. The record lists version 1.0.4 as the first without the flaw, so updating grav-plugin-api to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.31% chance of exploitation within 30 days, which is low compared with other CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update grav-plugin-api to 1.0.4 or a later version.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
- Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Grav | grav-plugin-api | before 1.0.4 | 1.0.4 |
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
- NoneNo account or login is needed.
- User interaction
- RequiredA user must take an action such as opening a file or link.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- 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:N/UI:R/S:C/C:H/I:H/A:H. Scored by CNA (vulncheck.com).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 9.4 | Critical | CNA (vulncheck.com) |
| CVSS 3.1 | 9.6 | Critical | CNA (vulncheck.com) |
Official description
The Grav API plugin (grav-plugin-api) before 1.0.4 does not validate the origin of the client-supplied admin_base_url field in the POST /api/v1/auth/forgot-password endpoint. The sanitizeHttpUrl() function only checks that the URL scheme is http/https and never verifies the host against the server's own origin, so an attacker can supply an arbitrary host. As a result, an unauthenticated attacker can cause the password reset email sent to a victim to contain a reset link pointing at an attacker-controlled server; when the victim follows the link, the valid reset token is disclosed to the attacker, enabling full account takeover. The vulnerable base URL can also be influenced via the Referer or Origin headers.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: URL Redirection to Untrusted Site
The web application accepts a user-controlled input that specifies a link to an external site, and uses that link in a redirect.
How developers prevent this class of flaw
- Use an intermediate disclaimer page that provides the user with a clear warning that they are leaving the current site. Implement a long timeout before the redirect occurs, or force the user to click on the link. Be careful to avoid XSS problems (CWE-79) when generating the disclaimer page.
- When the set of acceptable objects, such as filenames or URLs, is limited or known, create a mapping from a set of fixed input values (such as numeric IDs) to the actual filenames or URLs, and reject all other inputs. For example, ID 1 could map to /login.asp and ID 2 could map to http://www.example.com/. Features such as the ESAPI AccessReferenceMap provide this capability.
- Ensure that no externally-supplied requests are honored by requiring that all redirect requests include a unique nonce generated by the application. Be sure that the nonce is not predictable (CWE-330).
More URL Redirection to Untrusted Site vulnerabilities (CWE-601)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other references
Other vulnerabilities in grav-plugin-api
- 9.8 Critical severity
- 7.2 High severity
- 8.7 High severity
- 8.7 High severity
- 8.7 High severity
- 8.7 High severity
Recent URL Redirection to Untrusted Site vulnerabilities
- 8.1 High severity
- 7.1 High severity
- 7.4 High severity
- 8.8 High severity
- 7.2 High severity
- 8.2 High severity
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