# CVE-2017-7793: firefox: A use-after-free vulnerability can occur in the Fetch API when the worker or the associated window are freed when sti...

CVE-2017-7793 is fixed in 12 products on 1 platform, first by firefox 56.0+build6-0ubuntu1, released October 1, 2017. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2017-7793
- Priority: Routine
- CVSS: n/a (Medium)
- EPSS: 0.0227
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Oct 1, 2017

## Description

A use-after-free vulnerability can occur in the Fetch API when the worker or the associated window are freed when still in use, resulting in a potentially exploitable crash. This vulnerability affects Firefox < 56, Firefox ESR < 52.4, and Thunderbird < 52.4.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | firefox Ubuntu 18.04.6 LTS (bionic) | 56.0+build6-0ubuntu1 | [firefox 56.0+build6-0ubuntu1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-firefox-56.0-build6-0ubuntu1.md) | Oct 1, 2017 |
| Linux | firefox-globalmenu Ubuntu 18.04.6 LTS (bionic) | 56.0+build6-0ubuntu1 | [firefox-globalmenu 56.0+build6-0ubuntu1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-firefox-globalmenu-56.0-build6-0ubuntu1.md) | Oct 1, 2017 |
| Linux | firefox-mozsymbols Ubuntu 18.04.6 LTS (bionic) | 56.0+build6-0ubuntu1 | [firefox-mozsymbols 56.0+build6-0ubuntu1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-firefox-mozsymbols-56.0-build6-0ubuntu1.md) | Oct 1, 2017 |
| Linux | firefox-testsuite Ubuntu 18.04.6 LTS (bionic) | 56.0+build6-0ubuntu1 | [firefox-testsuite 56.0+build6-0ubuntu1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-firefox-testsuite-56.0-build6-0ubuntu1.md) | Oct 1, 2017 |
| Linux | thunderbird Ubuntu 18.04.6 LTS (bionic) | 1:52.4.0+build1-0ubuntu2 | [thunderbird 1:52.4.0+build1-0ubuntu2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-thunderbird-1-52.4.0-build1-0ubuntu2.md) | Oct 1, 2017 |
| Linux | thunderbird-globalmenu Ubuntu 18.04.6 LTS (bionic) | 1:52.4.0+build1-0ubuntu2 | [thunderbird-globalmenu 1:52.4.0+build1-0ubuntu2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-thunderbird-globalmenu-1-52.4.0-build1-0ubuntu2.md) | Oct 1, 2017 |
| Linux | thunderbird-gnome-support Ubuntu 18.04.6 LTS (bionic) | 1:52.4.0+build1-0ubuntu2 | [thunderbird-gnome-support 1:52.4.0+build1-0ubuntu2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-thunderbird-gnome-support-1-52.4.0-build1-0ubuntu2.md) | Oct 1, 2017 |
| Linux | thunderbird-mozsymbols Ubuntu 18.04.6 LTS (bionic) | 1:52.4.0+build1-0ubuntu2 | [thunderbird-mozsymbols 1:52.4.0+build1-0ubuntu2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-thunderbird-mozsymbols-1-52.4.0-build1-0ubuntu2.md) | Oct 1, 2017 |
| Linux | thunderbird-testsuite Ubuntu 18.04.6 LTS (bionic) | 1:52.4.0+build1-0ubuntu2 | [thunderbird-testsuite 1:52.4.0+build1-0ubuntu2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-thunderbird-testsuite-1-52.4.0-build1-0ubuntu2.md) | Oct 1, 2017 |
| Linux | xul-ext-calendar-timezones Ubuntu 18.04.6 LTS (bionic) | 1:52.4.0+build1-0ubuntu2 | [xul-ext-calendar-timezones 1:52.4.0+build1-0ubuntu2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-xul-ext-calendar-timezones-1-52.4.0-build1-0ubuntu2.md) | Oct 1, 2017 |
| Linux | xul-ext-gdata-provider Ubuntu 18.04.6 LTS (bionic) | 1:52.4.0+build1-0ubuntu2 | [xul-ext-gdata-provider 1:52.4.0+build1-0ubuntu2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-xul-ext-gdata-provider-1-52.4.0-build1-0ubuntu2.md) | Oct 1, 2017 |
| Linux | xul-ext-lightning Ubuntu 18.04.6 LTS (bionic) | 1:52.4.0+build1-0ubuntu2 | [xul-ext-lightning 1:52.4.0+build1-0ubuntu2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-xul-ext-lightning-1-52.4.0-build1-0ubuntu2.md) | Oct 1, 2017 |

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Data as of 2026-11-07T06:34:28Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo