CVE-2026-55878
Symfony: Path Traversal in symfony/ux-toolkit Allows Arbitrary File Write and Read via Crafted Recipe Manifest
Symfony UX is a JavaScript ecosystem for Symfony. From 2.32.0 before 2.36.1 and from 3.0.0 before 3.2.0, the ux:install console command installs files from a recipe kit by copying paths listed in a copy-files map, and because Path::isRelative() accepts paths like ../../../etc, a crafted or compromised kit can write attacker-controlled content to arbitrary locations or read local files outside the recipe directory. This issue is fixed in versions 2.36.1 and 3.2.0.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
7.8
Symfony: Path Traversal in symfony/ux-toolkit Allows Arbitrary File Write and Read via Crafted Recipe Manifest
Symfony UX is a JavaScript ecosystem for Symfony. From 2.32.0 before 2.36.1 and from 3.0.0 before 3.2.0, the ux:install console command installs files from a recipe kit by copying paths listed in a copy-files map, and because Path::isRelative() accepts paths like ../../../etc, a crafted or compromised kit can write attacker-controlled content to arbitrary locations or read local files outside the recipe directory. This issue is fixed in versions 2.36.1 and 3.2.0.
- Record
CVE-2026-55878- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-22
- Updated
- 2026-11-02
EUVDEUVD-2026-42443
7.8
Symfony UX is a JavaScript ecosystem for Symfony. From 2.32.0 before 2.36.1 and from 3.0.0 before 3.2.0, the ux:install console command installs files from a recipe kit by copying paths listed in a copy-files map, and because Path::isRelative() accepts paths like ../../../etc, a crafted or compromised kit can write attacker-controlled content to arbitrary locations or read local files outside the recipe directory. This issue is fixed in versions 2.36.1 and 3.2.0.
- Record
EUVD-2026-42443- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-p9xj-fpr2-jf2q
7.8
symfony/ux-toolkit: Path Traversal Allows Arbitrary File Write and Read via Crafted Recipe Manifest
Description
The ux:install console command installs files from a recipe kit by copying paths listed in a copy-files map. The only guard against malicious paths was Path::isRelative(), which returns true for paths like ../../../etc. Path::join() then resolves the .. segments without complaint, so the final path can escape the intended directory entirely. A crafted or compromised kit can therefore write attacker-controlled content to arbitrary locations on the developer's machine or CI runner.
Because the copy operation creates missing parent directories and can overwrite existing files silently (with --force or in non-interactive environments), an attacker who controls a kit can overwrite files such as controllers, git hooks, or .env to achieve code execution. The source side of copy-files is symmetrically affected, enabling local file reads outside the recipe directory.
Resolution
The fix introduces an Assert::pathDoesNotEscapeDirectory() helper that rejects any copy-files source or destination path containing a .. segment, regardless of whether / or \ is used as the separator. This check is enforced in both RecipeManifest (which also guards the source Finder) and File. As a last line of defense, the installer re-verifies the fully resolved paths with Path::isBasePath() immediately before each filesystem read and write.
Credits
Symfony would like to thank Pascal Cescon for reporting the issue and Hugo Alliaume for providing the fix.
- Record
GHSA-p9xj-fpr2-jf2q- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-22
- Updated
- 2026-11-02
NVD
7.8
Symfony UX is a JavaScript ecosystem for Symfony. From 2.32.0 before 2.36.1 and from 3.0.0 before 3.2.0, the ux:install console command installs files from a recipe kit by copying paths listed in a copy-files map, and because Path::isRelative() accepts paths like ../../../etc, a crafted or compromised kit can write attacker-controlled content to arbitrary locations or read local files outside the recipe directory. This issue is fixed in versions 2.36.1 and 3.2.0.
- Record
CVE-2026-55878- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-22
- Updated
- 2026-11-02
OSV
7.8
Symfony: Path Traversal in symfony/ux-toolkit Allows Arbitrary File Write and Read via Crafted Recipe Manifest
Symfony UX is a JavaScript ecosystem for Symfony. From 2.32.0 before 2.36.1 and from 3.0.0 before 3.2.0, the ux:install console command installs files from a recipe kit by copying paths listed in a copy-files map, and because Path::isRelative() accepts paths like ../../../etc, a crafted or compromised kit can write attacker-controlled content to arbitrary locations or read local files outside the recipe directory. This issue is fixed in versions 2.36.1 and 3.2.0.
- Record
CVE-2026-55878- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-22
- Updated
- 2026-11-02
OSVGHSA-p9xj-fpr2-jf2q
7.8
symfony/ux-toolkit: Path Traversal Allows Arbitrary File Write and Read via Crafted Recipe Manifest
Description
The ux:install console command installs files from a recipe kit by copying paths listed in a copy-files map. The only guard against malicious paths was Path::isRelative(), which returns true for paths like ../../../etc. Path::join() then resolves the .. segments without complaint, so the final path can escape the intended directory entirely. A crafted or compromised kit can therefore write attacker-controlled content to arbitrary locations on the developer's machine or CI runner.
Because the copy operation creates missing parent directories and can overwrite existing files silently (with --force or in non-interactive environments), an attacker who controls a kit can overwrite files such as controllers, git hooks, or .env to achieve code execution. The source side of copy-files is symmetrically affected, enabling local file reads outside the recipe directory.
Resolution
The fix introduces an Assert::pathDoesNotEscapeDirectory() helper that rejects any copy-files source or destination path containing a .. segment, regardless of whether / or \ is used as the separator. This check is enforced in both RecipeManifest (which also guards the source Finder) and File. As a last line of defense, the installer re-verifies the fully resolved paths with Path::isBasePath() immediately before each filesystem read and write.
Credits
Symfony would like to thank Pascal Cescon for reporting the issue and Hugo Alliaume for providing the fix.
- Record
GHSA-p9xj-fpr2-jf2q- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-22
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
symfony/ux-toolkitPackagist |
2.32.0 up to 2.36.1 | 2.36.1 |
symfony/ux-toolkitPackagist |
3.0.0 up to 3.2.0 | 3.2.0 |
symfony/ux-toolkitPackagist |
2.32.0 up to 2.36.1, plus listed versions v2.32.0v2.33.0v2.34.0v2.35.0v2.36.0 |
2.36.1 |
symfony/ux-toolkitPackagist |
3.0.0 up to 3.2.0, plus listed versions v3.0.0v3.1.0 |
3.2.0 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-55878 is a high vulnerability (CVSS 7.8) in Symfony Ux, published June 19, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.19%, the 8th percentile. Fixed in symfony/ux-toolkit 2.36.1.
References
github.com/symfony/ux/security/advisories/GHSA-p9xj-fpr2-jf2q
github.com/symfony/ux/commit/7b4ddf3764bf269a1b5fde5bf03c4bce568694e4
github.com/symfony/ux/releases/tag/v2.36.1
github.com/symfony/ux/releases/tag/v3.2.0
github.com/FriendsOfPHP/security-advisories/blob/master/symfony/ux-toolkit/CVE-2026-55878.yaml
github.com/advisories/GHSA-p9xj-fpr2-jf2q
github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55878.json
nvd.nist.gov/vuln/detail/CVE-2026-55878
github.com/symfony/ux