{"api_version":"1","generated_at":"2026-11-11T01:10:20+00:00","cve":"CVE-2026-126136","urls":{"html":"https://cve.report/CVE-2026-126136","api":"https://cve.report/api/cve/CVE-2026-126136.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-126136","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-126136"},"summary":{"title":"OAuth2 access token could be sent over an unencrypted connection with Exchange accounts","description":"For Exchange accounts using EWS or Microsoft Graph with OAuth2 authentication, Thunderbird sent the OAuth2 access token to the server even when the configured server URL used unencrypted HTTP. An attacker able to observe network traffic could obtain the token and use it to access the user's mailbox until the token expired. An attacker positioned on the network during account setup could cause such a URL to be configured. This vulnerability was fixed in Thunderbird 160 and Thunderbird 153.7.","state":"PUBLISHED","assigner":"mozilla","published_at":"2026-11-10 19:21:14","updated_at":"2026-11-10 21:19:27"},"problem_types":[],"metrics":[],"references":[{"url":"https://bugzilla.mozilla.org/show_bug.cgi?id=2085865","name":"https://bugzilla.mozilla.org/show_bug.cgi?id=2085865","refsource":"security@mozilla.org","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-128/","name":"https://www.mozilla.org/security/advisories/mfsa2026-128/","refsource":"security@mozilla.org","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-129/","name":"https://www.mozilla.org/security/advisories/mfsa2026-129/","refsource":"security@mozilla.org","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-126136","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-126136","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Mozilla","product":"Thunderbird","version":"unaffected 153.7 153.* rpm","platforms":[]},{"source":"CNA","vendor":"Mozilla","product":"Thunderbird","version":"unaffected 160 * rpm","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[{"source":"CNA","value":"Álvaro Chico Martínez","lang":"en"}],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"product":"Thunderbird","vendor":"Mozilla","versions":[{"lessThanOrEqual":"153.*","status":"unaffected","version":"153.7","versionType":"rpm"},{"lessThanOrEqual":"*","status":"unaffected","version":"160","versionType":"rpm"}]}],"credits":[{"lang":"en","value":"Álvaro Chico Martínez"}],"descriptions":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"For Exchange accounts using EWS or Microsoft Graph with OAuth2 authentication, Thunderbird sent the OAuth2 access token to the server even when the configured server URL used unencrypted HTTP. An attacker able to observe network traffic could obtain the token and use it to access the user's mailbox until the token expired. An attacker positioned on the network during account setup could cause such a URL to be configured. This vulnerability was fixed in Thunderbird 160 and Thunderbird 153.7."}],"value":"For Exchange accounts using EWS or Microsoft Graph with OAuth2 authentication, Thunderbird sent the OAuth2 access token to the server even when the configured server URL used unencrypted HTTP. An attacker able to observe network traffic could obtain the token and use it to access the user's mailbox until the token expired. An attacker positioned on the network during account setup could cause such a URL to be configured. This vulnerability was fixed in Thunderbird 160 and Thunderbird 153.7."}],"providerMetadata":{"dateUpdated":"2026-11-10T20:24:08.458Z","orgId":"f16b083a-5664-49f3-a51e-8d479e5ed7fe","shortName":"mozilla"},"references":[{"url":"https://bugzilla.mozilla.org/show_bug.cgi?id=2085865"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-128/"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-129/"}],"title":"OAuth2 access token could be sent over an unencrypted connection with Exchange accounts"}},"cveMetadata":{"assignerOrgId":"f16b083a-5664-49f3-a51e-8d479e5ed7fe","assignerShortName":"mozilla","cveId":"CVE-2026-126136","datePublished":"2026-11-10T18:59:58.290Z","dateReserved":"2026-11-10T18:59:57.660Z","dateUpdated":"2026-11-10T20:24:08.458Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-11-10 19:21:14","lastModifiedDate":"2026-11-10 21:19:27","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"126136","Ordinal":"1","Title":"OAuth2 access token could be sent over an unencrypted connection","CVE":"CVE-2026-126136","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"126136","Ordinal":"1","NoteData":"For Exchange accounts using EWS or Microsoft Graph with OAuth2 authentication, Thunderbird sent the OAuth2 access token to the server even when the configured server URL used unencrypted HTTP. An attacker able to observe network traffic could obtain the token and use it to access the user's mailbox until the token expired. An attacker positioned on the network during account setup could cause such a URL to be configured. This vulnerability was fixed in Thunderbird 160 and Thunderbird 153.7.","Type":"Description","Title":"OAuth2 access token could be sent over an unencrypted connection"}]}}}