CVE-2026-92240

Out-of-bounds read in IMAP response parser

CVE-2026-92240 is fixed in 135 products on 3 platforms, first by Mozilla Thunderbird 156.0, released September 10, 2026. It is not reported as exploited. Patch Radar priority: Urgent.

UrgentFixed on 3 platforms
CVSS
9.1
critical
Exploitation
None reported
No vendor assessment
CISA KEV
Not listed
Not in the Known Exploited Vulnerabilities catalog
EPSS
0.0063
50th percentile

A malicious or compromised IMAP server can trigger an out-of-bounds read in the IMAP response parser by sending an untagged '* ID' response, crashing Thunderbird. The affected parsing path is reachable before authentication. This vulnerability was fixed in Thunderbird 156, Thunderbird 140.16, and Thunderbird 153.3.

Where it's fixed

ProductFixed inFixReleased
Windows apps
Mozilla Thunderbird (af) 156.0 Mozilla Thunderbird (af) 156.0 Sep 15, 2026
Mozilla Thunderbird (ar) 156.0 Mozilla Thunderbird (ar) 156.0 Sep 15, 2026
Mozilla Thunderbird (ast) 156.0 Mozilla Thunderbird (ast) 156.0 Sep 15, 2026
Mozilla Thunderbird (be) 156.0 Mozilla Thunderbird (be) 156.0 Sep 15, 2026
Mozilla Thunderbird (bg) 156.0 Mozilla Thunderbird (bg) 156.0 Sep 15, 2026
Mozilla Thunderbird (br) 156.0 Mozilla Thunderbird (br) 156.0 Sep 15, 2026
Mozilla Thunderbird (ca) 156.0 Mozilla Thunderbird (ca) 156.0 Sep 15, 2026
Mozilla Thunderbird (cak) 156.0 Mozilla Thunderbird (cak) 156.0 Sep 15, 2026
Mozilla Thunderbird (cs) 156.0 Mozilla Thunderbird (cs) 156.0 Sep 15, 2026
Mozilla Thunderbird (cy) 156.0 Mozilla Thunderbird (cy) 156.0 Sep 15, 2026
Mozilla Thunderbird (da) 156.0 Mozilla Thunderbird (da) 156.0 Sep 15, 2026
Mozilla Thunderbird (de) 156.0 Mozilla Thunderbird (de) 156.0 Sep 15, 2026
Mozilla Thunderbird (dsb) 156.0 Mozilla Thunderbird (dsb) 156.0 Sep 15, 2026
Mozilla Thunderbird (el) 156.0 Mozilla Thunderbird (el) 156.0 Sep 15, 2026
Mozilla Thunderbird (en-CA) 156.0 Mozilla Thunderbird (en-CA) 156.0 Sep 15, 2026
Mozilla Thunderbird (en-GB) 156.0 Mozilla Thunderbird (en-GB) 156.0 Sep 15, 2026
Mozilla Thunderbird (en-US) 156.0 Mozilla Thunderbird (en-US) 156.0 Sep 15, 2026
Mozilla Thunderbird (es-AR) 156.0 Mozilla Thunderbird (es-AR) 156.0 Sep 15, 2026
Mozilla Thunderbird (es-ES) 156.0 Mozilla Thunderbird (es-ES) 156.0 Sep 15, 2026
Mozilla Thunderbird (es-MX) 156.0 Mozilla Thunderbird (es-MX) 156.0 Sep 15, 2026
Mozilla Thunderbird (et) 156.0 Mozilla Thunderbird (et) 156.0 Sep 15, 2026
Mozilla Thunderbird (eu) 156.0 Mozilla Thunderbird (eu) 156.0 Sep 15, 2026
Mozilla Thunderbird (fi) 156.0 Mozilla Thunderbird (fi) 156.0 Sep 15, 2026
Mozilla Thunderbird (fr) 156.0 Mozilla Thunderbird (fr) 156.0 Sep 15, 2026
Mozilla Thunderbird (fy-NL) 156.0 Mozilla Thunderbird (fy-NL) 156.0 Sep 15, 2026
Mozilla Thunderbird (ga-IE) 156.0 Mozilla Thunderbird (ga-IE) 156.0 Sep 15, 2026
Mozilla Thunderbird (gd) 156.0 Mozilla Thunderbird (gd) 156.0 Sep 15, 2026
Mozilla Thunderbird (gl) 156.0 Mozilla Thunderbird (gl) 156.0 Sep 15, 2026
Mozilla Thunderbird (he) 156.0 Mozilla Thunderbird (he) 156.0 Sep 15, 2026
Mozilla Thunderbird (hr) 156.0 Mozilla Thunderbird (hr) 156.0 Sep 15, 2026
Mozilla Thunderbird (hsb) 156.0 Mozilla Thunderbird (hsb) 156.0 Sep 15, 2026
Mozilla Thunderbird (hu) 156.0 Mozilla Thunderbird (hu) 156.0 Sep 15, 2026
Mozilla Thunderbird (hy-AM) 156.0 Mozilla Thunderbird (hy-AM) 156.0 Sep 15, 2026
Mozilla Thunderbird (id) 156.0 Mozilla Thunderbird (id) 156.0 Sep 15, 2026
Mozilla Thunderbird (is) 156.0 Mozilla Thunderbird (is) 156.0 Sep 15, 2026
Mozilla Thunderbird (it) 156.0 Mozilla Thunderbird (it) 156.0 Sep 15, 2026
Mozilla Thunderbird (ja) 156.0 Mozilla Thunderbird (ja) 156.0 Sep 15, 2026
Mozilla Thunderbird (ka) 156.0 Mozilla Thunderbird (ka) 156.0 Sep 15, 2026
Mozilla Thunderbird (kab) 156.0 Mozilla Thunderbird (kab) 156.0 Sep 15, 2026
Mozilla Thunderbird (kk) 156.0 Mozilla Thunderbird (kk) 156.0 Sep 15, 2026
Mozilla Thunderbird (ko) 156.0 Mozilla Thunderbird (ko) 156.0 Sep 15, 2026
Mozilla Thunderbird (lt) 156.0 Mozilla Thunderbird (lt) 156.0 Sep 15, 2026
Mozilla Thunderbird (lv) 156.0 Mozilla Thunderbird (lv) 156.0 Sep 15, 2026
Mozilla Thunderbird (ms) 156.0 Mozilla Thunderbird (ms) 156.0 Sep 15, 2026
Mozilla Thunderbird (nb-NO) 156.0 Mozilla Thunderbird (nb-NO) 156.0 Sep 15, 2026
Mozilla Thunderbird (nl) 156.0 Mozilla Thunderbird (nl) 156.0 Sep 15, 2026
Mozilla Thunderbird (nn-NO) 156.0 Mozilla Thunderbird (nn-NO) 156.0 Sep 15, 2026
Mozilla Thunderbird (pa-IN) 156.0 Mozilla Thunderbird (pa-IN) 156.0 Sep 15, 2026
Mozilla Thunderbird (pl) 156.0 Mozilla Thunderbird (pl) 156.0 Sep 15, 2026
Mozilla Thunderbird (pt-BR) 156.0 Mozilla Thunderbird (pt-BR) 156.0 Sep 15, 2026
Mozilla Thunderbird (pt-PT) 156.0 Mozilla Thunderbird (pt-PT) 156.0 Sep 15, 2026
Mozilla Thunderbird (rm) 156.0 Mozilla Thunderbird (rm) 156.0 Sep 15, 2026
Mozilla Thunderbird (ro) 156.0 Mozilla Thunderbird (ro) 156.0 Sep 15, 2026
Mozilla Thunderbird (ru) 156.0 Mozilla Thunderbird (ru) 156.0 Sep 15, 2026
Mozilla Thunderbird (sk) 156.0 Mozilla Thunderbird (sk) 156.0 Sep 15, 2026
Mozilla Thunderbird (sl) 156.0 Mozilla Thunderbird (sl) 156.0 Sep 15, 2026
Mozilla Thunderbird (sq) 156.0 Mozilla Thunderbird (sq) 156.0 Sep 15, 2026
Mozilla Thunderbird (sr) 156.0 Mozilla Thunderbird (sr) 156.0 Sep 15, 2026
Mozilla Thunderbird (sv-SE) 156.0 Mozilla Thunderbird (sv-SE) 156.0 Sep 15, 2026
Mozilla Thunderbird (th) 156.0 Mozilla Thunderbird (th) 156.0 Sep 15, 2026
Mozilla Thunderbird (tr) 156.0 Mozilla Thunderbird (tr) 156.0 Sep 15, 2026
Mozilla Thunderbird (uk) 156.0 Mozilla Thunderbird (uk) 156.0 Sep 15, 2026
Mozilla Thunderbird (uz) 156.0 Mozilla Thunderbird (uz) 156.0 Sep 15, 2026
Mozilla Thunderbird (vi) 156.0 Mozilla Thunderbird (vi) 156.0 Sep 15, 2026
Mozilla Thunderbird (zh-CN) 156.0 Mozilla Thunderbird (zh-CN) 156.0 Sep 15, 2026
Mozilla Thunderbird (zh-TW) 156.0 Mozilla Thunderbird (zh-TW) 156.0 Sep 15, 2026
Mozilla Thunderbird ESR (af) 153.3.0 Mozilla Thunderbird ESR (af) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (ar) 153.3.0 Mozilla Thunderbird ESR (ar) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (ast) 153.3.0 Mozilla Thunderbird ESR (ast) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (be) 153.3.0 Mozilla Thunderbird ESR (be) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (bg) 153.3.0 Mozilla Thunderbird ESR (bg) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (br) 153.3.0 Mozilla Thunderbird ESR (br) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (ca) 153.3.0 Mozilla Thunderbird ESR (ca) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (cak) 153.3.0 Mozilla Thunderbird ESR (cak) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (cs) 153.3.0 Mozilla Thunderbird ESR (cs) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (cy) 153.3.0 Mozilla Thunderbird ESR (cy) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (da) 153.3.0 Mozilla Thunderbird ESR (da) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (de) 153.3.0 Mozilla Thunderbird ESR (de) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (dsb) 153.3.0 Mozilla Thunderbird ESR (dsb) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (el) 153.3.0 Mozilla Thunderbird ESR (el) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (en-CA) 153.3.0 Mozilla Thunderbird ESR (en-CA) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (en-GB) 153.3.0 Mozilla Thunderbird ESR (en-GB) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (en-US) 153.3.0 Mozilla Thunderbird ESR (en-US) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (es-AR) 153.3.0 Mozilla Thunderbird ESR (es-AR) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (es-ES) 153.3.0 Mozilla Thunderbird ESR (es-ES) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (es-MX) 153.3.0 Mozilla Thunderbird ESR (es-MX) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (et) 153.3.0 Mozilla Thunderbird ESR (et) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (eu) 153.3.0 Mozilla Thunderbird ESR (eu) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (fi) 153.3.0 Mozilla Thunderbird ESR (fi) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (fr) 153.3.0 Mozilla Thunderbird ESR (fr) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (fy-NL) 153.3.0 Mozilla Thunderbird ESR (fy-NL) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (ga-IE) 153.3.0 Mozilla Thunderbird ESR (ga-IE) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (gd) 153.3.0 Mozilla Thunderbird ESR (gd) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (gl) 153.3.0 Mozilla Thunderbird ESR (gl) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (he) 153.3.0 Mozilla Thunderbird ESR (he) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (hr) 153.3.0 Mozilla Thunderbird ESR (hr) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (hsb) 153.3.0 Mozilla Thunderbird ESR (hsb) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (hu) 153.3.0 Mozilla Thunderbird ESR (hu) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (hy-AM) 153.3.0 Mozilla Thunderbird ESR (hy-AM) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (id) 153.3.0 Mozilla Thunderbird ESR (id) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (is) 153.3.0 Mozilla Thunderbird ESR (is) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (it) 153.3.0 Mozilla Thunderbird ESR (it) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (ja) 153.3.0 Mozilla Thunderbird ESR (ja) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (ka) 153.3.0 Mozilla Thunderbird ESR (ka) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (kab) 153.3.0 Mozilla Thunderbird ESR (kab) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (kk) 153.3.0 Mozilla Thunderbird ESR (kk) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (ko) 153.3.0 Mozilla Thunderbird ESR (ko) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (lt) 153.3.0 Mozilla Thunderbird ESR (lt) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (lv) 153.3.0 Mozilla Thunderbird ESR (lv) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (ms) 153.3.0 Mozilla Thunderbird ESR (ms) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (nb-NO) 153.3.0 Mozilla Thunderbird ESR (nb-NO) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (nl) 153.3.0 Mozilla Thunderbird ESR (nl) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (nn-NO) 153.3.0 Mozilla Thunderbird ESR (nn-NO) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (pa-IN) 153.3.0 Mozilla Thunderbird ESR (pa-IN) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (pl) 153.3.0 Mozilla Thunderbird ESR (pl) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (pt-BR) 153.3.0 Mozilla Thunderbird ESR (pt-BR) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (pt-PT) 153.3.0 Mozilla Thunderbird ESR (pt-PT) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (rm) 153.3.0 Mozilla Thunderbird ESR (rm) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (ro) 153.3.0 Mozilla Thunderbird ESR (ro) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (ru) 153.3.0 Mozilla Thunderbird ESR (ru) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (sk) 153.3.0 Mozilla Thunderbird ESR (sk) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (sl) 153.3.0 Mozilla Thunderbird ESR (sl) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (sq) 153.3.0 Mozilla Thunderbird ESR (sq) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (sr) 153.3.0 Mozilla Thunderbird ESR (sr) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (sv-SE) 153.3.0 Mozilla Thunderbird ESR (sv-SE) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (th) 153.3.0 Mozilla Thunderbird ESR (th) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (tr) 153.3.0 Mozilla Thunderbird ESR (tr) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (uk) 153.3.0 Mozilla Thunderbird ESR (uk) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (uz) 153.3.0 Mozilla Thunderbird ESR (uz) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (vi) 153.3.0 Mozilla Thunderbird ESR (vi) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (zh-CN) 153.3.0 Mozilla Thunderbird ESR (zh-CN) 153.3.0 Sep 16, 2026
Mozilla Thunderbird ESR (zh-TW) 153.3.0 Mozilla Thunderbird ESR (zh-TW) 153.3.0 Sep 16, 2026
macOS
Mozilla Thunderbird 156.0 Mozilla Thunderbird 156.0 Sep 10, 2026
Linux
MozillaThunderbird · sles 15.7 153.4.0-150400.13.6.1 SUSE-SU-2026:4627-1 Nov 7, 2026
thunderbird · Debian 12.15 (bookworm) 1:140.16.0esr-1~deb12u1 DEBIAN-CVE-2026-92240 Sep 17, 2026
thunderbird · Debian 13.5 (trixie) 1:140.16.0esr-1~deb13u1 DEBIAN-CVE-2026-92240 Sep 17, 2026
thunderbird · Debian 14 1:153.3.0esr-1 DEBIAN-CVE-2026-92240 Sep 17, 2026
thunderbird · RHEL 10 140.16.0-1.el10_0 RHSA-2026:81392 Sep 30, 2026
thunderbird · RHEL 8 0:140.16.0-1.el8_10 RHSA-2026:73971 Oct 1, 2026
thunderbird · RHEL 9 0:140.16.0-1.el9_8 RHSA-2026:70642 Sep 24, 2026
thunderbird · almalinux 10 140.16.0-1.el10_2.alma.1 ALSA-2026:73130 Sep 29, 2026
thunderbird · almalinux 8 140.16.0-1.el8_10.alma.1 ALSA-2026:73971 Sep 30, 2026
thunderbird · almalinux 9 140.16.0-1.el9_8.alma.1 ALSA-2026:70642 Sep 23, 2026
thunderbird · ol 10 0:140.16.0-1.0.1.el10_2 ELSA-2026-73130 Sep 29, 2026
thunderbird · ol 8 0:140.16.0-1.0.1.el8_10 ELSA-2026-73971 Oct 1, 2026
thunderbird · ol 9 0:140.16.0-1.0.1.el9_8 ELSA-2026-70642 Sep 24, 2026
thunderbird · rocky 10 0:140.16.0-1.el10_2 RLSA-2026:73130 Sep 30, 2026
thunderbird · rocky 8 0:140.16.0-1.el8_10 RLSA-2026:73971 Oct 1, 2026
thunderbird · rocky 9 0:140.16.0-1.el9_8 RLSA-2026:70642 Sep 25, 2026

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