CVE-2023-4583

Browsing Context potentially not cleared when closing Private Window

HIGH

7.5

CVSS Score

Published: September 11, 2023 at 08:02 AM UTC

Updated: June 17, 2026 at 06:38 AM UTC

3 products affected across 1 vendorFirefoxThunderbirdFirefox ESR

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Severity

HIGH7.5

Exploit prediction

EPSS 0.7%

SSVC

No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Firefox · Mozilla

95%

v < 117

Affected range stops below 117, so it looks safe — our inference, not a vendor statement

Affected range stops below 117.0, so it looks safe — our inference, not a vendor statement

Firefox ESR · Mozilla

95%

v < 115.2

Affected range stops below 115.2, so it looks safe — our inference, not a vendor statement

Thunderbird · Mozilla

95%

v < 115.2

Affected range stops below 115.2, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

References (4)

Issue Tracking

Source: [email protected]

https://bugzilla.mozilla.org/show_bug.cgi?id=1842030

Vendor Advisory

Source: [email protected]

https://www.mozilla.org/security/advisories/mfsa2023-34/

Vendor Advisory

Source: [email protected]

https://www.mozilla.org/security/advisories/mfsa2023-36/

Vendor Advisory

Source: [email protected]

https://www.mozilla.org/security/advisories/mfsa2023-38/

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHCISA-ADP

Attack Vector: NETWORK
Complexity: LOW
Privileges: NONE
User Interaction: NONE
Scope: UNCHANGED
Confidentiality: NONE
Integrity: HIGH
Availability: NONE

Vector?

Quick Info

StatusMODIFIED

CWE

NVD-CWE-noinfoCWE-754

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