Mozilla patches Thunderbird data integrity flaws
Mozilla released updates for Thunderbird versions 140.12.1 and 152.0.1 addressing multiple vulnerabilities that could lead to data integrity compromise and denial of service.
Sourcecert.ssi.gouv.fr — open the original
What to check
- Applies to
- The 2 CVEs named below. Whether you run an affected version is not assessed: check the versions the source lists.
- Exploitation
- No exploitation in the wild and no public exploit is recorded for the CVEs named.
The French CERT has issued an advisory regarding multiple security vulnerabilities discovered in Mozilla Thunderbird. The vulnerabilities affect versions prior to 140.12.1 and versions prior to 152.0.1. According to the advisory, these flaws could allow an attacker to compromise the integrity of data and cause denial of service conditions.
Mozilla has released security bulletins MFSA2026-63 and MFSA2026-64 on June 30, 2026, addressing these issues. The vulnerabilities are tracked as CVE-2026-57962 and CVE-2026-57963. Users are advised to consult Mozilla's security advisories and apply the available patches to mitigate these risks.
The advisory emphasizes the importance of updating to the patched versions to protect against potential attacks that could exploit these vulnerabilities to manipulate data or disrupt email service availability.
Mentioned in this report
Source reporting: https://www.cert.ssi.gouv.fr/avis/CERTFR-2026-AVI-0827
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