polis: Improper Neutralization of Alternate XSS Syntax
CVE-2026-33506 is a high-severity improper neutralization of alternate XSS syntax vulnerability in polis from Ory, with a CVSS 3.1 base score of 8.8 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. Affected polis versions: < 26.2.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.48% 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
- Check which version of polis you run against the affected versions below, and install the vendor's latest release.
- 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
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
- LowLimited modification of data is possible.
- Availability
- LowPerformance or availability is reduced.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:L. Scored by CNA (github.com).
Official description
Ory Polis, formerly known as BoxyHQ Jackson, bridges or proxies a SAML login flow to OAuth 2.0 or OpenID Connect. Versions prior to 26.2.0 contain a DOM-based Cross-Site Scripting (XSS) vulnerability in Ory Polis's login functionality. The application improperly trusts a URL parameter (`callbackUrl`), which is passed to `router.push`. An attacker can craft a malicious link that, when opened by an authenticated user (or an unauthenticated user that later logs in), performs a client-side redirect and executes arbitrary JavaScript in the context of their browser. This could lead to credential theft, internal network pivoting, and unauthorized actions performed on behalf of the victim. Version 26.2.0 contains a patch for the issue.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Neutralization of Alternate XSS Syntax
The product does not neutralize or incorrectly neutralizes user-controlled input for alternate script syntax.
How developers prevent this class of flaw
- Resolve all input to absolute or canonical representations before processing.
- With Struts, write all data from form beans with the bean's filter attribute set to true.
More Improper Neutralization of Alternate XSS Syntax vulnerabilities (CWE-87)
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
- github.com/ory/polis/security/advisories/GHSA-3wjr-6gw8-9j22Exploit, Mitigation
Patches and release notes
- github.com/ory/polis/releases/tag/v26.2.0Product, Release Notes
Recent Improper Neutralization of Alternate XSS Syntax vulnerabilities
- 9.3 Critical severity
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