VulnerabilityPublished 2 Mar 2026

CVE-2025-58107: Microsoft Exchange · Cleartext Transmission

Source CVE Database V5

Not known to be exploited · CVSS 7.5 High.

Data as of 26 Oct 2026, 13:47 UTC

CVSS 3.1 base score

7.5High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.2% chance of exploitation in 30 days – higher than 17% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: None
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 2 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

AI-suggested

To mitigate CVE-2025-58107, organizations should: 1) Apply any patches or updates released by Microsoft addressing this vulnerability as soon as they become available. 2) Enforce the use of secure transport protocols such as TLS 1.2 or higher for all Exchange ActiveSync communications to ensure encryption of data in transit. 3) Review and harden Exchange server configurations to disable any fallback to unencrypted or weakly encrypted protocols. 4) Implement network segmentation and monitoring to detect unusual traffic patterns or potential man-in-the-middle attacks targeting EAS traffic. 5) Encourage or enforce the use of updated Samsung device firmware and security patches that may address client-side aspects of this vulnerability. 6) Consider deploying multi-factor authentication (MFA) for Exchange access to reduce the impact of credential compromise. 7) Conduct regular security audits and penetration testing focused on Exchange ActiveSync configurations and mobile device integrations. 8) Educate users about the risks of using unsecured networks and encourage the use of VPNs when accessing corporate resources remotely. These measures collectively reduce the risk of exploitation and limit the exposure of sensitive data.

Description

In Microsoft Exchange through 2019, Exchange ActiveSync (EAS) configurations on on-premises servers may transmit sensitive data from Samsung mobile devices in cleartext, including the user's name, e-mail address, device ID, bearer token, and base64-encoded password.

Impact

The primary impact of CVE-2025-58107 is the compromise of confidentiality due to the exposure of sensitive user data transmitted in cleartext. Attackers intercepting this data could gain access to user credentials, session tokens, and device identifiers, enabling unauthorized access to corporate email accounts and potentially lateral movement within an organization's network. This could lead to data breaches, espionage, and disruption of business operations. The vulnerability does not affect data integrity or availability directly but significantly increases the risk of account compromise and subsequent attacks. Organizations relying on on-premises Microsoft Exchange servers with EAS configurations and Samsung mobile devices are particularly vulnerable. The exposure of bearer tokens and passwords in cleartext also raises the risk of credential theft and replay attacks. Given the network-based attack vector and lack of required privileges or user interaction, exploitation could be automated and widespread if attackers gain network access. The absence of known exploits in the wild currently reduces immediate risk but does not diminish the potential for future attacks.

CWE-319Cleartext Transmission of Sensitive Information (opens in a new tab)
Base weaknessLikelihood of exploit: HighOWASP Top 10 A04:2025: Cryptographic Failures (opens in a new tab)
The product transmits sensitive or security-critical data in cleartext in a communication channel that can be sniffed by unauthorized actors.
Architecture and Design
Before transmitting, encrypt the data using reliable, confidentiality-protecting cryptographic protocols.
Implementation
When using web applications with SSL, use SSL for the entire session from login to logout, not just for the initial login page.
Implementation
When designing hardware platforms, ensure that approved encryption algorithms (such as those recommended by NIST) protect paths from security critical data to trusted user applications.
OWASP Cheat Sheets
Transport Layer Protection (opens in a new tab)
TLS Cipher String (opens in a new tab)
User Privacy Protection (opens in a new tab)
Password Storage (opens in a new tab)
Cryptographic Storage (opens in a new tab)
OWASP ASVS 4.0.3
V8.3.1 (opens in a new tab)
V9.2.2 (opens in a new tab)
V1.9.1 (opens in a new tab)
Attack patterns
Session Sidejacking (opens in a new tab)
Harvesting Information via API Event Monitoring (opens in a new tab)
Signature Spoofing by Mixing Signed and Unsigned Content (opens in a new tab)
Sniff Application Code (opens in a new tab)
Interception (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

geochen.medium.com/microsoft-activesync-legacy-protocol-plaintext-credential-and-token-exposure-vulnerability-b0fad89014fa (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 9 Mar 2026, 17:25 UTC

WeaknessesCWE-319

Technical details

References

Community reviews

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