renovate: URL Redirection to Untrusted Site
CVE-2026-88881 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 44.11.3 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 44.11.3 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 44.11.3 | 44.11.3 |
| 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, a dependency update tool, follows pagination links supplied by the GitHub server in the HTTP `Link` header when interacting with GitHub.com, GitHub Enterprise Cloud, or GitHub Enterprise Server, and sends the credentials configured for that host to the URL given as the 'next' page. Because the pagination URL is not validated against the host originally contacted, a malicious or compromised GitHub server can return a `Link` header pointing to an attacker-controlled host and cause Renovate to disclose those credentials to it. Exploitation requires that the GitHub server Renovate talks to (as the repository host or as a datasource such as github-releases, github-tags, or git-refs) is already malicious or compromised. The issue is fixed in renovate 44.11.3 (npm and renovate/renovate container images), Mend Renovate CE/EE images and the mend-renovate-ce helm chart 15.4.0, and the mend-renovate-enterprise-edition helm chart 10.4.0. There is no workaround; the pre-existing RENOVATE_X_REBASE_PAGINATION_LINKS option disables the new host check and should only be used with servers that intentionally use different pagination hosts.
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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