SB2026062424 - Multiple vulnerabilities in IBM Db2
Published: June 24, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 3 vulnerabilities.
1) Improper Encoding or Escaping of Output (CVE-ID: CVE-2026-34480)
CWE-ID: CWE-116 - Improper Encoding or Escaping of Output
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Green
The vulnerability allows a remote attacker to cause log event loss.
The vulnerability exists due to improper output neutralization in XmlLayout when processing log messages or MDC values containing XML 1.0 forbidden characters. A remote attacker can supply crafted input containing forbidden characters to cause log event loss.
The impact depends on the StAX implementation in use: built-in JRE StAX may produce malformed XML that downstream parsers reject, while alternative implementations may throw an exception during the logging call so the event is delivered only to Log4j's internal status logger.
2) Improper Certificate Validation (CVE-ID: CVE-2026-34477)
CWE-ID: CWE-295 - Improper Certificate Validation
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
The vulnerability allows a remote attacker to perform a man-in-the-middle attack.
The vulnerability exists due to improper certificate validation in the TLS hostname verification handling of the verifyHostName attribute in Log4j Core SSL configuration when establishing TLS connections for SMTP, Socket, or Syslog appenders. A remote attacker can present a certificate issued by a trusted certificate authority to perform a man-in-the-middle attack.
The issue occurs only when TLS is configured via a nested SSL configuration element, and it does not affect the HTTP appender.
3) Improper Output Neutralization for Logs (CVE-ID: CVE-2026-34478)
CWE-ID: CWE-117 - Improper Output Neutralization for Logs
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
The vulnerability allows a remote attacker to inject arbitrary log entries.
The vulnerability exists due to improper neutralization of CRLF sequences in Rfc5424Layout when processing logged data with direct Rfc5424Layout configuration using TCP framing. A remote attacker can supply specially crafted input containing CRLF sequences to inject arbitrary log entries.
Only users of stream-based syslog services who configure Rfc5424Layout directly are affected. Users of the SyslogAppender are not affected.
Remediation
Install update from vendor's website.