How severe is CVE-2025-1015?

CVE-2025-1015 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2025-1015 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (68th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-1015?

CVE-2025-1015 affects Mozilla Thunderbird. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2025-1015?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2025-1015 have an EU (EUVD) identifier?

Yes. CVE-2025-1015 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-1970.

When was CVE-2025-1015 published?

CVE-2025-1015 was published on 2025-02-04 and last updated on 2026-06-17.

CVE-2025-1015

CVE-2025-1015 is a medium-severity vulnerability in Mozilla Thunderbird with a CVSS 3.x base score of 5.4. 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-79.

Key facts

Severity: Medium (CVSS 3.x base score 5.4)
EPSS exploit prediction: 1% (68th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-1970
Weakness: CWE-79
Affected product: Mozilla Thunderbird
Published: 2025-02-04
Last modified: 2026-06-17

Description

The Thunderbird Address Book URI fields contained unsanitized links. This could be used by an attacker to create and export an address book containing a malicious payload in a field. For example, in the “Other” field of the Instant Messaging section. If another user imported the address book, clicking on the link could result in opening a web page inside Thunderbird, and that page could execute (unprivileged) JavaScript. This vulnerability was fixed in Thunderbird 128.7 and Thunderbird 135.

Frequently asked questions

What is CVE-2025-1015?: The Thunderbird Address Book URI fields contained unsanitized links. This could be used by an attacker to create and export an address book containing a malicious payload in a field. For example, in the “Other” field of the Instant Messaging section. If another user imported the address book, clicking on the link could result in opening a web page inside Thunderbird, and that page could execute (unprivileged) JavaScript. This vulnerability was fixed in Thunderbird 128.7 and Thunderbird 135.
How severe is CVE-2025-1015?: CVE-2025-1015 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2025-1015 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (68th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-1015?: CVE-2025-1015 affects Mozilla Thunderbird. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-1015?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-1015 have an EU (EUVD) identifier?: Yes. CVE-2025-1015 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-1970.
When was CVE-2025-1015 published?: CVE-2025-1015 was published on 2025-02-04 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:*

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