CVE-2026-113866
When setting up an account, Thunderbird's Exchange AutoDiscover lookup also queried the domain's…
- Risk score
- 41/100
- CVSS
- 5.9 v3.1
- Exploit chance (30 days)
- 0.4%
- Published
- 20 Oct 2026
Open in the live forecast Today's forecast
What to know
- What it is
- When setting up an account, Thunderbird's Exchange AutoDiscover lookup also queried the domain's AutoDiscover service over plain HTTP. Due to a bug, that unencrypted request included the credentials the user had entered, allowing a network attacker to obtain the user's password. This vulnerability was fixed in Thunder…
- Affected
- See advisory
- Fix
- Apply the vendor's security update; see the linked advisory.
- Exploitation
- No known exploitation
Why it is Yellow
- CVSS 5.9 medium
References
Original description
When setting up an account, Thunderbird's Exchange AutoDiscover lookup also queried the domain's AutoDiscover service over plain HTTP. Due to a bug, that unencrypted request included the credentials the user had entered, allowing a network attacker to obtain the user's password. This vulnerability was fixed in Thunderbird 158.0.1 and Thunderbird 153.5.1.
Last activity 20 Oct 2026. Patch Forecast updates every hour.