CVE-2026-126136

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-126136", "assignerOrgId": "f16b083a-5664-49f3-a51e-8d479e5ed7fe", "state": "PUBLISHED", "assignerShortName": "mozilla", "dateReserved": "2026-11-10T18:59:57.660Z", "datePublished": "2026-11-10T18:59:58.290Z", "dateUpdated": "2026-11-10T20:24:08.458Z"}, "containers": {"cna": {"affected": [{"product": "Thunderbird", "vendor": "Mozilla", "versions": [{"status": "unaffected", "version": "153.7", "lessThanOrEqual": "153.*", "versionType": "rpm"}, {"status": "unaffected", "version": "160", "lessThanOrEqual": "*", "versionType": "rpm"}]}], "descriptions": [{"lang": "en", "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.", "supportingMedia": [{"type": "text/html", "base64": false, "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."}]}], "title": "OAuth2 access token could be sent over an unencrypted connection with Exchange accounts", "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/"}], "credits": [{"lang": "en", "value": "\u00c1lvaro Chico Mart\u00ednez"}], "providerMetadata": {"orgId": "f16b083a-5664-49f3-a51e-8d479e5ed7fe", "shortName": "mozilla", "dateUpdated": "2026-11-10T20:24:08.458Z"}}}}

{}

{"affected": [{"affectedData": [{"product": "Thunderbird", "vendor": "Mozilla", "versions": [{"lessThanOrEqual": "153.*", "status": "unaffected", "version": "153.7", "versionType": "rpm"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "160", "versionType": "rpm"}]}], "source": "security@mozilla.org"}], "cveTags": [], "descriptions": [{"lang": "en", "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."}], "id": "CVE-2026-126136", "lastModified": "2026-11-10T21:19:27.973", "metrics": {}, "published": "2026-11-10T19:21:14.313", "references": [{"source": "security@mozilla.org", "url": "https://bugzilla.mozilla.org/show_bug.cgi?id=2085865"}, {"source": "security@mozilla.org", "url": "https://www.mozilla.org/security/advisories/mfsa2026-128/"}, {"source": "security@mozilla.org", "url": "https://www.mozilla.org/security/advisories/mfsa2026-129/"}], "sourceIdentifier": "security@mozilla.org", "vulnStatus": "Awaiting Analysis"}

{"bugzilla": {"description": "thunderbird: OAuth2 access token could be sent over an unencrypted connection with Exchange accounts", "id": "2571464", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2571464"}, "csaw": false, "cvss3": {"cvss3_base_score": "6.1", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N", "status": "draft"}, "cwe": "CWE-319", "details": ["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.", "A flaw was found in Thunderbird. The Mozilla Foundation's Security Advisory describes the following issue:\nFor 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."], "name": "CVE-2026-126136", "package_state": [{"cpe": "cpe:/a:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "rhel10/thunderbird-flatpak", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/a:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "thunderbird", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:rhel_els:6", "fix_state": "Out of support scope", "package_name": "thunderbird", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:rhel_els:7", "fix_state": "Out of support scope", "package_name": "thunderbird", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/a:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "thunderbird", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/a:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "thunderbird", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-11-11T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-126136\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-126136\nhttps://www.mozilla.org/security/advisories/mfsa2026-129/#CVE-2026-126136"], "statement": "Red Hat Product Security rates the severity of this flaw as determined by the Mozilla Foundation Security Advisory.", "threat_severity": "Moderate"}

{"created": "2026-11-12T03:45:21.915326+00:00", "updated": "2026-11-12T21:30:09.381495+00:00", "vendors": []}