CVE-2025-26696 | Crafted email message incorrectly shown as being encrypted

Certain crafted MIME email messages that claimed to contain an encrypted OpenPGP message, which instead contained an OpenPGP signed message, were wrongly shown as being encrypted. This vulnerability was fixed in Thunderbird 136 and Thunderbird 128.8.

Published: 2025-03-10 Last update: 2026-04-13 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-26696 is rated Moderate Risk (40.1/100): CVSS High severity, with low exploitation likelihood (EPSS 0.15%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-26696

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-04 0.16% 0.15% -0.01%
2 2026-04-21 0.11% 0.16% +0.05%
3 2026-04-18 — 0.11% —

Full EPSS history (8 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-26696

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.0 3.1 HIGH
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:L Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 2.2 4.7 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2025-26696

OS Trackers for CVE-2025-26696

vendor priority summary link
alpine — CVE-2025-26696: 1 source package rows (thunderbird); 66 state rows across 2 repos (3.22-community, edge-community); fixed 0, open 66. https://security.alpinelinux.org/vuln/CVE-2025-26696
debian not yet assigned CVE-2025-26696 not yet assigned priority: Debian including 1 source packages (thunderbird), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2025-26696
gentoo high CVE-2025-26696: 1 GLSA(s) (202505-03), 2 atom(s) (mail-client/thunderbird, mail-client/thunderbird-bin); latest impact high. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2025-26696
redhat medium — https://access.redhat.com/security/cve/CVE-2025-26696
suse high — https://www.suse.com/security/cve/CVE-2025-26696/
ubuntu medium CVE-2025-26696 medium priority: Ubuntu including 1 source packages (thunderbird), 6 status rows across 6 suites (focal, jammy, noble, oracular, plucky, upstream): not-affected 3, released 2, DNE 1. https://ubuntu.com/security/CVE-2025-26696

Affected software / configurations for CVE-2025-26696

Vendor Product Version Raw CPE
mozilla thunderbird < 128.8.0 cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*
mozilla thunderbird >= 129.0, < 136.0 cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*

References for CVE-2025-26696

cvelogic Threat Intelligence