CVE-2023-4583

Name: CVE-2023-4583
Creator: NVD / NIST
Published: 2023-09-11T09:15:09.68+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 0.56%

Last modified Jun 17, 2026

CVE-2023-4583 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. When checking if the Browsing Context had been discarded in `HttpBaseChannel`, if the load group was not available then it was assumed to have already been discarded which was not always the case for private channels after the private session had ended. This vulnerability affects Firefox < 117, Firefox ESR < 115.2, and Thunderbird < 115.2.. EPSS estimates a 0.56% chance of exploitation in the next 30 days.

Description

When checking if the Browsing Context had been discarded in `HttpBaseChannel`, if the load group was not available then it was assumed to have already been discarded which was not always the case for private channels after the private session had ended. This vulnerability affects Firefox < 117, Firefox ESR < 115.2, and Thunderbird < 115.2.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

EPSS Probability

0.56%

42.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-754

Affected Software

Vendor	Product	Versions
Mozilla	Firefox	< 117.0
Mozilla	Firefox Esr	< 115.2
Mozilla	Thunderbird	< 115.2

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1842030Issue Tracking
https://www.mozilla.org/security/advisories/mfsa2023-34/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2023-36/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2023-38/Vendor Advisory
https://bugzilla.mozilla.org/show_bug.cgi?id=1842030Issue Tracking
https://www.mozilla.org/security/advisories/mfsa2023-34/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2023-36/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2023-38/Vendor Advisory

Timeline

Published: Sep 11, 2023
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2023-4583?

How severe is CVE-2023-4583?

CVE-2023-4583 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 0.56% probability of exploitation in the next 30 days.

How do I fix CVE-2023-4583?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2023-4583?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST