Improper Encoding or Escaping of Output

Apache Log4j's JsonTemplateLayout https://logging.apache.org/log4j/2.x/manual/json-template-layout.html , in versions up to and including 2.25.3, produces invalid JSON output when log events contain non-finite floating-point values (NaN, Infinity, or -Infinity), which are prohibited by RFC 8259. This may cause downstream log processing systems to reject or fail to index affected records. An attacker can exploit this issue only if both of the following conditions are met: * The application uses JsonTemplateLayout. * The application logs a MapMessage, or logs an object directly (e.g., via Logger.info(Object), which wraps it in an ObjectMessage), where the message contains an attacker-controlled floating-point value. Users are advised to upgrade to Apache Log4j JSON Template Layout 2.25.4, which corrects this issue. Note: The fix released in version 2.25.4 did not cover all affected code paths. CVE-2026-49844 was assigned to the remaining issue, which concerns the MapMessage.asJson() serialization in Apache Log4j API and is fixed in versions 2.25.5 and 2.26.1.Show less

Apache Log4j Core's XmlLayout https://logging.apache.org/log4j/2.x/manual/layouts.html#XmlLayout , in versions up to and including 2.25.3, fails to sanitize characters forbidden by the XML 1.0 specification https://www.w3.org/TR/xml/#charsets producing invalid XML output whenever a log message or MDC value contains such characters. The impact depends on the StAX implementation in use: * JRE built-in StAX: Forbidden characters are silently written to the output, producing malformed XML. Conforming parsers must reject such documents with a fatal error, which may cause downstream log-processing systems to drop the affected records. * Alternative StAX implementations (e.g., Woodstox https://github.com/FasterXML/woodstox , a transitive dependency of the Jackson XML Dataformat module): An exception is thrown during the logging call, and the log event is never delivered to its intended appender, only to Log4j's internal status logger. Users are advised to upgrade to Apache Log4j Core 2.25.4, which corrects this issue by sanitizing forbidden characters before XML output.Show less

The Log4j1XmlLayout from the Apache Log4j 1-to-Log4j 2 bridge fails to escape characters forbidden by the XML 1.0 standard, producing malformed XML output. Conforming XML parsers are required to reject documents containing such characters with a fatal error, which may cause downstream log processing systems to drop or fail to index affected records. Two groups of users are affected: * Those using Log4j1XmlLayout directly in a Log4j Core 2 configuration file. * Those using the Log4j 1 configuration compatibility layer with org.apache.log4j.xml.XMLLayout specified as the layout class. Users are advised to upgrade to Apache Log4j 1-to-Log4j 2 bridge version 2.25.4, which corrects this issue. Note: The Apache Log4j 1-to-Log4j 2 bridge is deprecated and will not be present in Log4j 3. Users are encouraged to consult the Log4j 1 to Log4j 2 migration guide https://logging.apache.org/log4j/2.x/migrate-from-log4j1.html , and specifically the section on eliminating reliance on the bridge.Show less

Improper Encoding or Escaping of Output vulnerability in the JsonAccessLogValve component of Apache Tomcat. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.20, from 10.1.0-M1 through 10.1.53, from 9.0.40 through 9.0.116. Users are recommended to upgrade to version 11.0.21, 10.1.54 or 9.0.117 , which fix the issue.Show less

ChurchCRM is an open-source church management system. Prior to 7.1.0, a stored cross-site scripting vulnerability exists in PersonView.php due to incorrect use of sanitizeText() as an output sanitizer for HTML attribute context. The function only strips HTML tags, it does not escape quote characters allowing an attacker to break out of the href attribute and inject arbitrary JavaScript event handlers. Any authenticated user with the EditRecords role can store the payload in a person's Facebook field. The XSS fires against any user who views that person's profile page, including administrators, enabling session hijacking and full account takeover. This vulnerability is fixed in 7.1.0.Show less

lichess.org is the forever free, adless and open source chess server. Any approved streamer can inject arbitrary HTML into /streamer and the homepage “Live streams” widget by placing markup in their Twitch/YouTube stream title. CSP is present and blocks inline script execution, but the issue is still a server-side HTML injection sink. To trigger this, a Lichess account only needs to satisfy the normal streamer requirements and get approved. Per Streamer.canApply, that means an account older than 2 days with at least 15 games, or a verified/titled account. After moderator approval, once the streamer goes live, Lichess pulls the platform title and renders it into the UI as-is. No extra privileges are needed beyond a normal approved streamer profile. This vulnerability is fixed with commit 0d5002696ae705e1888bf77de107c73de57bb1b3.Show less

Handlebars provides the power necessary to let users build semantic templates. In versions 4.0.0 through 4.7.8, the Handlebars CLI precompiler (`bin/handlebars` / `lib/precompiler.js`) concatenates user-controlled strings — template file names and several CLI options — directly into the JavaScript it emits, without any escaping or sanitization. An attacker who can influence template filenames or CLI arguments can inject arbitrary JavaScript that executes when the generated bundle is loaded in Node.js or a browser. Version 4.7.9 fixes the issue. Some workarounds are available. First, validate all CLI inputs before invoking the precompiler. Reject filenames and option values that contain characters with JavaScript string-escaping significance (`"`, `'`, `;`, etc.). Second, use a fixed, trusted namespace string passed via a configuration file rather than command-line arguments in automated pipelines. Third, run the precompiler in a sandboxed environment (container with no write access to sensitive paths) to limit the impact of successful exploitation. Fourth, audit template filenames in any repository or package that is consumed by an automated build pipeline.Show less

OpenBao is an open source identity-based secrets management system. Prior to version 2.5.2, OpenBao installations that have an OIDC/JWT authentication method enabled and a role with `callback_mode=direct` configured are vulnerable to XSS via the `error_description` parameter on the page for a failed authentication. This allows an attacker access to the token used in the Web UI by a victim. The `error_description` parameter has been replaced with a static error message in v2.5.2. The vulnerability can be mitigated by removing any roles with `callback_mode` set to `direct`.Show less

Invoice Ninja is a source-available invoice, quote, project and time-tracking app built with Laravel. Invoice line item descriptions in Invoice Ninja v5.13.0 bypass the XSS denylist filter, allowing stored XSS payloads to execute when invoices are rendered in the PDF preview or client portal. The line item description field was not passed through `purify::clean()` before rendering. This is fixed in v5.13.4 by the vendor by adding `purify::clean()` to sanitize line item descriptions.Show less

Textpattern CMS version 4.9.0 contains a second-order cross-site scripting vulnerability that allows attackers to inject malicious scripts by exploiting improper sanitization of user-supplied input in Atom feed XML elements. Attackers can embed unescaped payloads in parameters such as category that are reflected into Atom fields like and , which execute as JavaScript when feed readers or CMS aggregators consume the feed and insert content into the DOM using unsafe methods.Show less

Heimdall is a cloud native Identity Aware Proxy and Access Control Decision service. When using Heimdall in envoy gRPC decision API mode with versions 0.7.0-alpha through 0.17.10, wrong encoding of the query URL string allows rules with non-wildcard path expressions to be bypassed. Envoy splits the requested URL into parts, and sends the parts individually to Heimdall. Although query and path are present in the API, the query field is documented to be always empty and the URL query is included in the path field. The implementation uses go's url library to reconstruct the url which automatically encodes special characters in the path. As a consequence, a parameter like /mypath?foo=bar to Path is escaped into /mypath%3Ffoo=bar. Subsequently, a rule matching /mypath no longer matches and is bypassed. The issue can only lead to unintended access if Heimdall is configured with an "allow all" default rule. Since v0.16.0, Heimdall enforces secure defaults and refuses to start with such a configuration unless this enforcement is explicitly disabled, e.g. via --insecure-skip-secure-default-rule-enforcement or the broader --insecure flag. This issue has been fixed in version 0.17.11.Show less

SuiteCRM is an open-source, enterprise-ready Customer Relationship Management (CRM) software application. Prior to versions 7.15.1 and 8.9.3, the value of the return_id request parameter is copied into the value of an HTML tag attribute which is an event handler and is encapsulated in double quotation marks. Versions 7.15.1 and 8.9.3 patch the issue. Users should also use a Content Security Policy (CSP) header to completely mitigate XSS.Show less

FreeScout is a free help desk and shared inbox built with PHP's Laravel framework. Versions 1.8.208 and below are vulnerable to Stored Cross-Site Scripting (XSS) through FreeScout's email notification templates. Incoming email bodies are stored in the database without sanitization and rendered unescaped in outgoing email notifications using Blade's raw output syntax {!! $thread->body !!}. An unauthenticated attacker can exploit this vulnerability by simply sending an email, and when opened by any subscribed agent or admin as part of their normal workflow, enabling universal HTML injection (phishing, tracking) and, in vulnerable email clients, JavaScript execution (session hijacking, credential theft, account takeover) affecting all recipients simultaneously. This issue has been fixed in version 1.8.209.Show less

OpenEMR is a free and open source electronic health records and medical practice management application. Prior to 8.0.0.2, users with the `Notes - my encounters` role can fill Eye Exam forms in patient encounters. The answers to the form can be printed out in PDF form. An arbitrary file read vulnerability was identified in the PDF creation function where the form answers are parsed as unescaped HTML, allowing an attacker to include arbitrary image files from the server in the generated PDF. Version 8.0.0.2 fixes the issue.Show less

jsPDF is a library to generate PDFs in JavaScript. Prior to version 4.2.1, user control of arguments of the `createAnnotation` method allows users to inject arbitrary PDF objects, such as JavaScript actions. If given the possibility to pass unsanitized input to the following method, a user can inject arbitrary PDF objects, such as JavaScript actions, which might trigger when the PDF is opened or interacted with the `createAnnotation`: `color` parameter. The vulnerability has been fixed in jsPDF@4.2.1. As a workaround, sanitize user input before passing it to the vulnerable API members.Show less

LeafKit is a templating language with Swift-inspired syntax. Prior to version 1.14.2, HTML escaping doesn't work correctly when a template prints a collection (Array / Dictionary) via `#(value)`. This can result in XSS, allowing potentially untrusted input to be rendered unescaped. Version 1.14.2 fixes the issue.Show less

The fix for CVE-2026-0672, which rejected control characters in http.cookies.Morsel, was incomplete. The Morsel.update(), |= operator, and unpickling paths were not patched, allowing control characters to bypass input validation. Additionally, BaseCookie.js_output() lacked the output validation applied to BaseCookie.output().Show less

Craft is a content management system (CMS). The fix for CVE-2025-35939 in craftcms/cms introduced a strip_tags() call in src/web/User.php to sanitize return URLs before they are stored in the session. However, strip_tags() only removes HTML tags (angle brackets) -- it does not inspect or filter URL schemes. Payloads like javascript:alert(document.cookie) contain no HTML tags and pass through strip_tags() completely unmodified, enabling reflected XSS when the return URL is rendered in an href attribute. This vulnerability is fixed in 5.9.7 and 4.17.3.Show less