What is CVE-2023-25729?

Permission prompts for opening external schemes were only shown for ContentPrincipals resulting in extensions being able to open them without user interaction via ExpandedPrincipals . This could lead to further malicious actions such as downloading files or interacting with software already installed on the system. This vulnerability affects Firefox < 110, Thunderbird < 102.8, and Firefox ESR < 102.8.

How severe is CVE-2023-25729?

CVE-2023-25729 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2023-25729 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (48th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-25729?

CVE-2023-25729 primarily affects Mozilla Firefox. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2023-25729?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2023-25729 published?

CVE-2023-25729 was published on 2023-06-02 and last updated on 2026-06-17.

CVE-2023-25729

Q: How severe is CVE-2023-25729?

CVE-2023-25729 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.

Q: Is CVE-2023-25729 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (48th percentile), an estimate of the probability of exploitation in the next 30 days.

Q: What products are affected by CVE-2023-25729?

CVE-2023-25729 primarily affects Mozilla Firefox. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

Q: How do I fix CVE-2023-25729?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Q: When was CVE-2023-25729 published?

CVE-2023-25729 was published on 2023-06-02 and last updated on 2026-06-17.

CVE-2023-25729 is a high-severity vulnerability in Mozilla Firefox with a CVSS 3.x base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-863.

Key facts

Severity: High (CVSS 3.x base score 8.8)
EPSS exploit prediction: 1% (48th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-863
Affected product: Mozilla Firefox
Published: 2023-06-02
Last modified: 2026-06-17

Description

Permission prompts for opening external schemes were only shown for <code>ContentPrincipals</code> resulting in extensions being able to open them without user interaction via <code>ExpandedPrincipals</code>. This could lead to further malicious actions such as downloading files or interacting with software already installed on the system. This vulnerability affects Firefox < 110, Thunderbird < 102.8, and Firefox ESR < 102.8.

Frequently asked questions

What is CVE-2023-25729?: Permission prompts for opening external schemes were only shown for <code>ContentPrincipals</code> resulting in extensions being able to open them without user interaction via <code>ExpandedPrincipals</code>. This could lead to further malicious actions such as downloading files or interacting with software already installed on the system. This vulnerability affects Firefox < 110, Thunderbird < 102.8, and Firefox ESR < 102.8.
How severe is CVE-2023-25729?: CVE-2023-25729 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2023-25729 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (48th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-25729?: CVE-2023-25729 primarily affects Mozilla Firefox. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2023-25729?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2023-25729 published?: CVE-2023-25729 was published on 2023-06-02 and last updated on 2026-06-17.

References

Affected products (3)

cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:firefox_esr:*:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*

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