CVE-2025-26696 Crafted email message incorrectly shown as being encrypted

What is CVE-2025-26696?

CVE-2025-26696 is a high-severity vulnerability in Mozilla Thunderbird, published on 10 Mar 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official 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.

Weakness: CWE-290

Which versions are affected by CVE-2025-26696?

It affects 1 product.

Products include Mozilla Thunderbird.

How do I fix CVE-2025-26696?

Upgrade to a fixed version.

Is CVE-2025-26696 being exploited?

There is no known exploitation of CVE-2025-26696 in the wild and no public exploit code.

Other vulnerabilities in Mozilla Thunderbird

• CVE-2026-92238 Ambiguous parsing of mail headers Critical 9.8
• CVE-2026-84637 Calendar invitation attachments could launch local executables Critical 9.8
• CVE-2021-43529 Memory corruption in Thunderbird Critical 9.8
• CVE-2019-11703 Memory corruption in Thunderbird Critical 9.8
• CVE-2019-11704 Memory corruption in Thunderbird Critical 9.8

All Mozilla Thunderbird vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2025-26696, GHSA-w56w-w5xr-q52m, UBUNTU-CVE-2025-26696.