CVE-2026-113868Medium· 5.3▾ SunlitWhen authenticating to a POP3 or SMTP server using NTLM, Thunderbird did not check whether the server's challenge was valid base64. A malicious server could send a challenge that caused Thunderbird to include uninitialized heap memory in…
▾ Sunlit zone — Low / medium · no exploitation signal
impact 29.2 · likelihood 0 · exploitation 0
Need a working PoC? Pro members can cast a request and our team develops one — it lands right here.
Stakeholder-Specific Vulnerability Categorization from CISA's ADP record at CVE.org: whether exploitation is observed, whether an attack can be automated, and how much of the system is at stake. The CVSS score shown above comes from the CISA ADP record, not NVD.
When authenticating to a POP3 or SMTP server using NTLM, Thunderbird did not check whether the server's challenge was valid base64. A malicious server could send a challenge that caused Thunderbird to include uninitialized heap memory in its NTLM response, disclosing that memory to the server. A challenge consisting only of base64 padding also caused an out-of-bounds read, crashing Thunderbird. This affected accounts configured to use NTLM or GSSAPI authentication. The uninitialized memory disclosure only affected NTLM. This vulnerability was fixed in Thunderbird 158.0.1 and Thunderbird 153.5.1.
ThunderbirdRefer to the linked advisories for vendor-supplied fixes and affected version ranges.
Connected by shared product, vendor, weakness, or advisory.
CVE-2026-113867NoneStanza injection in XMPP chat
CVE-2026-113866Medium· 5.9Account password sent unencrypted during Exchange account setup
CVE-2026-113869Medium· 5.4Use-after-free in S/MIME decryption during a security device password prompt
CVE-2026-113470Medium· 5.4Cryptographic issue in the Security Block-lists, Allow-lists, and other State component
CVE-2026-113399NoneIncorrect boundary conditions in the SVG component
CVE-2026-113400Medium· 5.4Uninitialized memory in the Audio/Video: cubeb component