CVE-2026-45066
MediumCVSS 6.1Exploitation Probability (EPSS)
Low risk21th percentile - higher than 21% of all known CVEs
Summary
A vulnerability in Symfony HtmlSanitizer allows bypassing the allowed host list due to differences in URL parsing between RFC 3986 and WHATWG, and incorrect checking of the <area href> tag against the media policy instead of the link policy. Affects versions from 6.1.0-BETA1 to 6.4.40, 7.4.12, and 8.0.12.
Risk Assessment
An attacker can inject malicious URLs into HTML content that are considered safe, potentially leading to data leakage or redirects to unauthorized sites.
Recommendation
Immediately update Symfony to version 6.4.40, 7.4.12, or 8.0.12, where this vulnerability is fixed.
Other vulnerabilities in Symfony
See all- CVE-2016-4423High
The attemptAuthentication function in Symfony before versions 2.3.41, 2.7.13, 2.8.6, and 3.0.6 does not limit the length of a username stored in a session. This allows remote attackers to cause a denial of service through a series of authentication attempts with long, non-existent usernames.
- CVE-2016-1902High
The nextBytes function in the SecureRandom class in Symfony before 2.3.37, 2.6.x before 2.6.13, and 2.7.x before 2.7.9 does not properly generate random numbers when used with PHP 5.x without the paragonie/random_compat library, and the openssl_random_pseudo_bytes function fails.
- CVE-2013-1397High
Symfony versions 2.0.x before 2.0.22, 2.1.x before 2.1.7, and 2.2.x are vulnerable to remote attacks that allow arbitrary PHP code execution via a serialized PHP object in the Yaml::parse or Yaml\Parser::parse functions.
- CVE-2013-1348High
The Yaml::parse function in Symfony 2.0.x before version 2.0.22 allows remote attackers to execute arbitrary PHP code via a PHP file, which is a different vulnerability than CVE-2013-1397.
- CVE-2026-47767Critical
A vulnerability in Symfony allows an attacker to manipulate the APP_ENV and APP_DEBUG environment variables via a crafted query string that bypasses the protection introduced in CVE-2024-50340. The issue stems from a discrepancy between parse_str() and the web SAPI, enabling attacker-controlled --env or --no-debug flags to be passed to the script.
- CVE-2026-45069Critical
In Symfony up to versions 6.4.40, 7.4.12, and 8.0.12, the OidcTokenHandler::verifyClaims() method registered audience (aud), issuer (iss), and expiry (exp) checkers but did not pass the mandatory claims list to ClaimCheckerManager::check(). This allowed a validly signed JWT missing those claims to pass verification.
- CVE-2026-45063Critical
A vulnerability in Symfony X509Authenticator allows an attacker with a trusted certificate to impersonate a victim by placing emailAddress= in another RDN value, such as CN, due to an unanchored regex.
- CVE-2016-2403Critical
Symfony before 2.8.6 and 3.x before 3.0.6 allows remote attackers to bypass authentication by logging in with an empty password and valid username, which triggers an unauthenticated bind.
- CVE-2026-48784Medium
A vulnerability in Symfony allows an attacker to manipulate URL paths via controlled route parameters. The UrlGenerator::doGenerate() function uses strtr() dot-segment encoding that skips every other chained ../ or ./ segment, enabling generation of URLs that collapse to a different path under RFC 3986 normalization.
- CVE-2026-48761Medium
In Symfony PHP framework from 6.1.0 to 6.4.41, 7.4.13, and 8.0.13, UrlAttributeSanitizer::getSupportedAttributes() omitted URL-bearing attributes on <object>, <applet>, <iframe>, and <img>, and <meta http-equiv="refresh"> URLs bypassed sanitization, allowing javascript: payloads. Fixed in versions 6.4.41, 7.4.13, and 8.0.13.
Original NVD description (English source)
Symfony is a PHP framework for web and console applications and a set of reusable PHP components. From 6.1.0-BETA1 until 6.4.40, 7.4.12, and 8.0.12, HtmlSanitizer URL sanitization can allow off-allowlist URLs through allowLinkHosts() or allowMediaHosts() because UrlSanitizer::parse() follows RFC 3986 while browsers follow WHATWG URL parsing, and because <area href> is checked against the media policy rather than the link policy. This issue is fixed in versions 6.4.40, 7.4.12, and 8.0.12.

