# CVE-2026-48784: Symfony: UrlGenerator Dot-Segment Encoding Skips Every Other Chained `../` or `./` → Generated URL Collapses Off-Route Under RFC 3986 Normalization > Attackers can craft route parameters to generate URLs that redirect to unintended paths due to flawed dot-segment encoding in Symfony's UrlGenerator. - **Severity:** Medium 5.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** A user has to click or open something - **Fix available:** Yes - **Published:** 14 Jul 2026 - **Updated:** 15 Jul 2026 - **Also known as:** DEBIAN-CVE-2026-48784, GHSA-h5x3-xfc9-m39h, UBUNTU-CVE-2026-48784 ## What is CVE-2026-48784? CVE-2026-48784 is a medium-severity vulnerability in Sensiolabs Symfony, published on 14 Jul 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link. ### Official description Symfony is a PHP framework for web and console applications and a set of reusable PHP components. Prior to 5.4.53, 6.4.41, 7.4.13, and 8.0.13, UrlGenerator::doGenerate() used strtr() dot-segment encoding that skipped every other chained ../ or ./ segment, allowing attacker-controlled route parameters to generate URLs that collapse to a different path under RFC 3986 normalization. This issue is fixed in versions 5.4.53, 6.4.41, 7.4.13, and 8.0.13. Weakness: CWE-601 (URL Redirection to Untrusted Site), CWE-172 (Improper Encoding or Decoding of Data) ## Which versions are affected by CVE-2026-48784? 16 open source packages ship an affected version, including symfony/routing and symfony/symfony. It affects 1 product. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `symfony/routing` | Packagist | All versions | 5.4.53 | | `symfony/routing` | Packagist | All versions | 5.4.53 | | `symfony/routing` | Packagist | From 6.0.0 | 6.4.41 | | `symfony/routing` | Packagist | From 6.0.0 | 6.4.41 | | `symfony/routing` | Packagist | From 7.0.0 | 7.4.13 | | `symfony/routing` | Packagist | From 7.0.0 | 7.4.13 | | `symfony/routing` | Packagist | From 8.0.0 | 8.0.13 | | `symfony/routing` | Packagist | From 8.0.0 | 8.0.13 | | `symfony/symfony` | Packagist | All versions | 5.4.53 | | `symfony/symfony` | Packagist | All versions | 5.4.53 | | `symfony/symfony` | Packagist | From 6.0.0 | 6.4.41 | | `symfony/symfony` | Packagist | From 6.0.0 | 6.4.41 | | `symfony/symfony` | Packagist | From 7.0.0 | 7.4.13 | | `symfony/symfony` | Packagist | From 7.0.0 | 7.4.13 | | `symfony/symfony` | Packagist | From 8.0.0 | 8.0.13 | | `symfony/symfony` | Packagist | From 8.0.0 | 8.0.13 | Products: Sensiolabs Symfony. ## How do I fix CVE-2026-48784? Upgrade symfony/routing to a fixed version for your release line: 5.4.53, 6.4.41, 7.4.13 or 8.0.13. ## Is CVE-2026-48784 being exploited? There is no known exploitation of CVE-2026-48784 in the wild and no public exploit code. ## Other vulnerabilities in Sensiolabs Symfony - [CVE-2019-11325](https://insights.sbomify.com/CVE-2019-11325/): Improper Input Validation in Symfony (critical 9.8) - [CVE-2017-11365](https://insights.sbomify.com/CVE-2017-11365/): Symfony Incorrect Access Control (critical 9.8) - [CVE-2019-10913](https://insights.sbomify.com/CVE-2019-10913/): Invalid HTTP method overrides allow possible XSS or other attacks in Symfony (critical 9.8) - [CVE-2018-11407](https://insights.sbomify.com/CVE-2018-11407/): Symfony Authentication Bypass (critical 9.8) - [CVE-2016-2403](https://insights.sbomify.com/CVE-2016-2403/): Symfony Authentication Bypass (critical 9.8) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2026-48784 and fix it if it is affected. What it is: CVE-2026-48784 is a medium-severity vulnerability in Sensiolabs Symfony, published on 14 Jul 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link. Exploitation: There is no known exploitation of CVE-2026-48784 in the wild and no public exploit code. Affected packages and fixed versions: - symfony/routing (Packagist): affected all versions; fixed in 5.4.53 - symfony/routing (Packagist): affected all versions; fixed in 5.4.53 - symfony/routing (Packagist): affected from 6.0.0; fixed in 6.4.41 - symfony/routing (Packagist): affected from 6.0.0; fixed in 6.4.41 - symfony/routing (Packagist): affected from 7.0.0; fixed in 7.4.13 - symfony/routing (Packagist): affected from 7.0.0; fixed in 7.4.13 - symfony/routing (Packagist): affected from 8.0.0; fixed in 8.0.13 - symfony/routing (Packagist): affected from 8.0.0; fixed in 8.0.13 - symfony/symfony (Packagist): affected all versions; fixed in 5.4.53 - symfony/symfony (Packagist): affected all versions; fixed in 5.4.53 - symfony/symfony (Packagist): affected from 6.0.0; fixed in 6.4.41 - symfony/symfony (Packagist): affected from 6.0.0; fixed in 6.4.41 Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2026-48784/ (Markdown: https://insights.sbomify.com/CVE-2026-48784/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2026-48784 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-48784 - OSV: https://osv.dev/vulnerability/CVE-2026-48784 --- From sbomify Insights: https://insights.sbomify.com/CVE-2026-48784/ Summaries are generated and may contain mistakes; the official description above is the record.