CVE-2025-26696Network attack vector

Encryption-status spoof via mismatched OpenPGP message

Published Mar 10, 2025 · Updated Apr 13, 2026

OpenPGP message spoofing in Mozilla Thunderbird before 136 and ESR before 128.8 allows remote attackers to misrepresent signed email as encrypted. The MIME message-status handling accepts a message advertised as encrypted even when its OpenPGP body is signed, then renders an encrypted indicator. Delivery of a crafted email is sufficient; recipients can be misled about confidentiality, but no message decryption or code execution is reported.

CVSS severity7.0
High
EPSS probability0.35%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

OpenPGP message spoofing in Mozilla Thunderbird before 136 and ESR before 128.8 allows remote attackers to misrepresent signed email as encrypted. The MIME message-status handling accepts a message advertised as encrypted even when its OpenPGP body is signed, then renders an encrypted indicator. Delivery of a crafted email is sufficient; recipients can be misled about confidentiality, but no message decryption or code execution is reported.

The record

CVE
CVE-2025-26696
Published
Mar 10, 2025
Updated
Apr 13, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-290
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 10, 2025CVE publishedPublication date reported by the CVE source.
  2. Apr 13, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.0CISA-ADPCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-290Authentication Bypass by Spoofing

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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