renovate: URL Redirection to Untrusted Site
CVE-2026-88882 is a high-severity URL redirection to untrusted site vulnerability in renovate from Renovatebot, with a CVSS 3.1 base score of 8.6 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 44.11.2 as the first without the flaw, so updating renovate to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.41% 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 renovate to 44.11.2 or a later version.
- Update renovate-ce to 15.4.0 or a later version.
- Update renovate-ee-server to 15.4.0 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.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Renovatebot | renovate | before 44.11.2 | 44.11.2 |
| Mend | renovate-ce | before 15.4.0 | 15.4.0 |
| Mend | renovate-ee-server | before 15.4.0 | 15.4.0 |
| Mend | renovate-ee-worker | before 15.4.0 | 15.4.0 |
| Mend | mend-renovate-ce | before 15.4.0 | 15.4.0 |
| Mend | mend-renovate-enterprise-edition | before 10.4.0 | 10.4.0 |
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
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- NoneNothing can be modified.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N. Scored by CNA (vulncheck.com).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 9.2 | Critical | CNA (vulncheck.com) |
| CVSS 3.1 | 8.6 | High | CNA (vulncheck.com) |
Official description
Renovate is a dependency update automation tool. In versions before 44.11.2 (and Mend Renovate CE/EE images and charts before 15.4.0, and mend-renovate-enterprise-edition helm chart before 10.4.0), when listing new package versions from a NuGet registry Renovate follows pagination URLs supplied by the registry in the HTTP `Link` header without verifying that the target has the same origin as the configured registry. Registry credentials are attached to the request for the 'next' page, so a malicious or compromised NuGet registry can return a `Link` header pointing at an attacker-controlled server and cause Renovate to send the registry credentials to that server. Exploitation requires the remote registry to be malicious or compromised; such a registry would normally already have received the credentials on the initial request, so the issue primarily allows the credentials to be delivered to an additional, attacker-chosen host. The fix restricts pagination to the same origin; the previous behaviour can be re-enabled with the RENOVATE_X_NUGET_PAGINATION_ALLOW_CROSS_ORIGIN option.
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: none, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Other references
Other vulnerabilities in renovate
- 8.5 High severity
- 8.5 High severity
- 7.1 High severity
- 7.8 High severity
- 7.0 High severity
- 8.6 High severity
Recent URL Redirection to Untrusted Site vulnerabilities
- 8.6 High severity
- 8.6 High severity
- 9.3 Critical severity
- 7.8 High severity
- 7.3 High severity
- 7.8 High severity
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