GHSA-HMR5-2XCR-V8PP

Vulnerability from github – Published: 2026-05-27 21:10 – Updated: 2026-05-27 21:10
VLAI
Summary
Symfony Vulnerable to stored XSS in WebProfiler CodeExtension::fileExcerpt() — Unescaped Non-PHP File Rendering
Details

Description

Symfony's profiler, a development only debug UI, renders source-code excerpts on several pages using Twig's custom file_excerpt filter. This filter renders PHP files via highlight_string() (which escapes HTML), but renders non-PHP files by splitting on \n and interpolating each line directly into <code>{$line}</code> with no escaping.

An attacker who can write arbitrary bytes into any file under the project root (including e.g. var/log/dev.log), achieves stored XSS against any developer who later opens that file in the profiler.

Resolution

The file_excerpt filter now properly escapes each line of non-PHP files using htmlspecialchars() before concatenating them.

The patch for this issue is available here for branch 6.4.

Credits

Symfony would like to thank Claude Mythos Preview (via Project Glasswing) for reporting the issue and providing the fix.

Severity
1.2 (Low)
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U
Show details on source website
To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "symfony/symfony"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.4.24"
            },
            {
              "fixed": "6.4.40"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "symfony/symfony"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "7.2.9"
            },
            {
              "fixed": "7.4.12"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "symfony/symfony"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "8.0.0"
            },
            {
              "fixed": "8.0.12"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "symfony/twig-bridge"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.4.24"
            },
            {
              "fixed": "6.4.40"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "symfony/web-profiler-bundle"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "7.2.9"
            },
            {
              "fixed": "7.4.12"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "symfony/web-profiler-bundle"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "8.0.0"
            },
            {
              "fixed": "8.0.12"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-45072"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-79"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-05-27T21:10:44Z",
    "nvd_published_at": null,
    "severity": "LOW"
  },
  "details": "### Description\n\nSymfony\u0027s profiler, a development only debug UI, renders source-code excerpts on several pages using Twig\u0027s custom `file_excerpt` filter. This filter renders PHP files via `highlight_string()` (which escapes HTML), but renders **non-PHP files** by splitting on `\\n` and interpolating each line directly into `\u003ccode\u003e{$line}\u003c/code\u003e` with no escaping. \n\nAn attacker who can write arbitrary bytes into any file under the project root (including e.g. `var/log/dev.log`), achieves **stored XSS** against any developer who later opens that file in the profiler.\n\n### Resolution\n\nThe `file_excerpt` filter now properly escapes each line of non-PHP files using `htmlspecialchars()` before concatenating them.\n\nThe patch for this issue is available [here](https://github.com/symfony/symfony/commit/863aa81c61166f1aa74b7732df316f76113acbdb) for branch 6.4.\n\n### Credits\n\nSymfony would like to thank Claude Mythos Preview (via Project Glasswing) for reporting the issue and providing the fix.",
  "id": "GHSA-hmr5-2xcr-v8pp",
  "modified": "2026-05-27T21:10:44Z",
  "published": "2026-05-27T21:10:44Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/symfony/symfony/security/advisories/GHSA-hmr5-2xcr-v8pp"
    },
    {
      "type": "WEB",
      "url": "https://github.com/symfony/symfony/commit/863aa81c61166f1aa74b7732df316f76113acbdb"
    },
    {
      "type": "WEB",
      "url": "https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/symfony/CVE-2026-45072.yaml"
    },
    {
      "type": "WEB",
      "url": "https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/twig-bridge/CVE-2026-45072.yaml"
    },
    {
      "type": "WEB",
      "url": "https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/web-profiler-bundle/CVE-2026-45072.yaml"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/symfony/symfony"
    },
    {
      "type": "WEB",
      "url": "https://symfony.com/cve-2026-45072"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Symfony Vulnerable to stored XSS in WebProfiler CodeExtension::fileExcerpt() \u2014 Unescaped Non-PHP File Rendering"
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.