CVE-2026-118177
Published:October 27, 2026
Updated:October 29, 2026
When looking for calendars in a directory on a server, during account setup or when adding a new network calendar, Thunderbird accepted calendar locations pointing to other servers, local files or network shares. A malicious server, or a network attacker when the lookup used plain HTTP, could make Thunderbird subscribe to such a location. On Windows this could leak the user's NTLM credentials to an attacker-controlled host on every calendar refresh, and changes to the calendar could be written to the attacker's share or overwrite a local file. This vulnerability was fixed in Thunderbird 159 and Thunderbird 153.6.
Affected Packages
https://github.com/thunderbird/thunderbird-desktop.git (GITHUB):
Affected version(s) >=THUNDERBIRD_82_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_87_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_88_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_89_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_90_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_91_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_92_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_93_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_94_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_95_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_96_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_97_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_98_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_99_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_100_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_101_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_102_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_103_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_104_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_105_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_106_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_107_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_108_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_109_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_110_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_111_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_112_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_113_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_114_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_115_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_116_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_117_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_118_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_119_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_120_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_121_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_122_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_123_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_124_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_125_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_126_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_127_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_128_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_129_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_130_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_131_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_132_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_133_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_134_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_135_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_136_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_137_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_138_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_139_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_140_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_141_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_142_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_143_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_144_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_145_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_146_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_147_0b1_BUILD1 <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_148_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_149_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_150_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_151_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_152_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASE || >=THUNDERBIRD_153_0b1_RELEASE <THUNDERBIRD_153_6_0esr_RELEASEFix Suggestion:
Update to version THUNDERBIRD_153_6_0esr_RELEASEhttps://github.com/thunderbird/thunderbird-desktop.git (GITHUB):
Affected version(s) >=THUNDERBIRD_154_0b1_RELEASE <THUNDERBIRD_159_0_RELEASE || >=THUNDERBIRD_155_0b1_RELEASE <THUNDERBIRD_159_0_RELEASE || >=THUNDERBIRD_156_0b1_RELEASE <THUNDERBIRD_159_0_RELEASE || >=THUNDERBIRD_157_0b1_RELEASE <THUNDERBIRD_159_0_RELEASE || >=THUNDERBIRD_158_0b1_RELEASE <THUNDERBIRD_159_0_RELEASE || >=THUNDERBIRD_159_0b1_RELEASE <THUNDERBIRD_159_0_RELEASEFix Suggestion:
Update to version THUNDERBIRD_159_0_RELEASERelated Resources (3)
Do you need more information?
Contact UsCVSS v4
Base Score:
6
Attack Vector
NETWORK
Attack Complexity
HIGH
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
PASSIVE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
NONE
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
5.3
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
NONE
Availability
NONE