SB20261109190 - Ubuntu update for ruby2.3

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Main Vulnerability Database SB20261109190

SB20261109190 - Ubuntu update for ruby2.3

Published: November 9, 2026

Security Bulletin ID SB20261109190
CSH Severity
High
Patch available
YES
Number of vulnerabilities 2
Exploitation vector Remote access
Highest impact Code execution

Breakdown by Severity

High 50% Medium 50%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 2 vulnerabilities.


1) Command injection (CVE-ID: CVE-2026-42258)

CWE-ID: CWE-77 - Command injection

CVSSv4: 5.7 [CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:A/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N]


The vulnerability allows an unprivileged local attacker to inject IMAP commands and delete mailboxes when a user triggers a vulnerable application command.

The vulnerability exists due to missing validation of Symbol arguments in net-imap when applications pass user-controlled input as Symbols to IMAP commands. An unprivileged local attacker can include CRLF sequences in a Symbol to terminate the original command and append a mailbox deletion command.


2) Buffer overflow (CVE-ID: CVE-2026-27820)

CWE-ID: CWE-120 - Buffer overflow

CVSSv4: 8.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N]


The vulnerability allows a remote attacker to cause memory corruption.

The vulnerability exists due to buffer overflow in zstream_buffer_ungets() function when parsing input within the Zlib::GzipReader. A remote attacker can provide crafted input that causes the buffer length to exceed its capacity to cause memory corruption.

User interaction is required.


Remediation

Install update from vendor's website.

References