CVE-2026-55856Network attack vector

Cleartext password disclosure via unchecked initial handshake

Published Aug 28, 2026 · Updated Aug 28, 2026

Credential disclosure in MariaDB Connector/J before 2.7.14, 3.3.5, 3.4.3, or 3.5.9 allows man-in-the-middle attackers to steal passwords. HandshakeResponse.encode() sends a mysql_clear_password response before the initial path checks the captured certificate fingerprint or plugin resistance. Exploitation requires verify-full or verify-ca mode, a password, no pinned certificate or trust store, and an active hostile server; the stolen credential grants the database account's existing access.

CVSS severity5.9
Medium
EPSS probability0.22%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Credential disclosure in MariaDB Connector/J before 2.7.14, 3.3.5, 3.4.3, or 3.5.9 allows man-in-the-middle attackers to steal passwords. HandshakeResponse.encode() sends a mysql_clear_password response before the initial path checks the captured certificate fingerprint or plugin resistance. Exploitation requires verify-full or verify-ca mode, a password, no pinned certificate or trust store, and an active hostile server; the stolen credential grants the database account's existing access.

The record

CVE
CVE-2026-55856
Published
Aug 28, 2026
Updated
Aug 28, 2026
Vendor
MariaDB
Product
MariaDB Connector/J
Classifications
CWE-522, T1557
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 28, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 28, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 2.7.14
  2. Affected versionversion=>= 3.0.0, < 3.3.5
  3. Affected versionversion=>= 3.4.0, < 3.4.3
  4. Affected versionversion=>= 3.5.0, < 3.5.9

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

MariaDB · MariaDB Connector/Jversion=< 2.7.14; version=>= 3.0.0, < 3.3.5; version=>= 3.4.0, < 3.4.3; version=>= 3.5.0, < 3.5.9

Published CVSS scores

5.9GitHubCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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-522Insufficiently Protected Credentials
T1557Adversary-in-the-Middle

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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