How severe is CVE-2025-26696?

CVE-2025-26696 has a CVSS 3.x base score of 7.0, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity low, and availability low.

Is CVE-2025-26696 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (25th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-26696?

CVE-2025-26696 affects Mozilla Thunderbird. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2025-26696?

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.

Does CVE-2025-26696 have an EU (EUVD) identifier?

Yes. CVE-2025-26696 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-7706.

When was CVE-2025-26696 published?

CVE-2025-26696 was published on 2025-03-10 and last updated on 2026-06-17.

CVE-2025-26696

CVE-2025-26696 is a high-severity vulnerability in Mozilla Thunderbird with a CVSS 3.x base score of 7.0. 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-290.

Key facts

Severity: High (CVSS 3.x base score 7.0)
EPSS exploit prediction: 0% (25th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-7706
Weakness: CWE-290
Affected product: Mozilla Thunderbird
Published: 2025-03-10
Last modified: 2026-06-17

Description

Certain crafted MIME email messages that claimed to contain an encrypted OpenPGP message, which instead contained an OpenPGP signed message, were wrongly shown as being encrypted. This vulnerability was fixed in Thunderbird 136 and Thunderbird 128.8.

Frequently asked questions

What is CVE-2025-26696?: Certain crafted MIME email messages that claimed to contain an encrypted OpenPGP message, which instead contained an OpenPGP signed message, were wrongly shown as being encrypted. This vulnerability was fixed in Thunderbird 136 and Thunderbird 128.8.
How severe is CVE-2025-26696?: CVE-2025-26696 has a CVSS 3.x base score of 7.0, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity low, and availability low.
Is CVE-2025-26696 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (25th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-26696?: CVE-2025-26696 affects Mozilla Thunderbird. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-26696?: 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.
Does CVE-2025-26696 have an EU (EUVD) identifier?: Yes. CVE-2025-26696 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-7706.
When was CVE-2025-26696 published?: CVE-2025-26696 was published on 2025-03-10 and last updated on 2026-06-17.

References

Affected products (1)

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

More vulnerabilities in Mozilla Thunderbird

CVE-2026-4692 — Critical (CVSS 10.0): Sandbox escape in the Responsive Design Mode component. This vulnerability was fixed in Firefox 149, Firefox ESR…
CVE-2026-4689 — Critical (CVSS 10.0): Sandbox escape due to incorrect boundary conditions, integer overflow in the XPCOM component. This vulnerability was…
CVE-2026-2778 — Critical (CVSS 10.0): Sandbox escape due to incorrect boundary conditions in the DOM: Core & HTML component. This vulnerability was fixed in…
CVE-2026-2776 — Critical (CVSS 10.0): Sandbox escape due to incorrect boundary conditions in the Telemetry component in External Software. This vulnerability…
CVE-2026-2768 — Critical (CVSS 10.0): Sandbox escape in the Storage: IndexedDB component. This vulnerability was fixed in Firefox 148, Firefox ESR 140.8,…
CVE-2026-2761 — Critical (CVSS 10.0): Sandbox escape in the Graphics: WebRender component. This vulnerability was fixed in Firefox 148, Firefox ESR 115.33,…

All CVEs affecting Mozilla Thunderbird →

Other CWE-290 vulnerabilities

CVE-2026-54782 — Critical (CVSS 10.0): CoreWCF is a port of the service side of Windows Communication Foundation (WCF) to .NET Core. Prior to 1.8.1 and 1.9.1,…
CVE-2026-48567 — Critical (CVSS 10.0): Authentication bypass by spoofing in Azure HorizonDB allows an unauthorized attacker to elevate privileges over a…
CVE-2026-6213 — Critical (CVSS 10.0): A vulnerability in Remote Spark SparkView before build 1122 allows an attacker to bypasses the local connection check…
CVE-2026-39858 — Critical (CVSS 10.0): Traefik is an HTTP reverse proxy and load balancer. Prior to versions 2.11.43, 3.6.14, and 3.7.0-rc.2, there is a high…
CVE-2025-66570 — Critical (CVSS 10.0): cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to 0.27.0, a vulnerability…
CVE-2025-34063 — Critical (CVSS 10.0): A cryptographic authentication bypass vulnerability exists in OneLogin AD Connector prior to 6.1.5 due to the exposure…

Browse all CWE-290 vulnerabilities →