CVE-2026-58013

A flaw was found in GLib. A buffer over-read can occur in g_io_channel_read_line_backend() in the giochannel.c file when a custom line terminator with a length greater than one is set, causing memcmp to read past the GString buffer. This vulnerability can cause a minor information disclosure of 7 bytes or a denial of service when the buffer over-read crosses a page boundary.

Any applications calling g_io_channel_set_line_term() with a multi-byte line terminator (length greater than one) and subsequently calling g_io_channel_read_line_backend() are vulnerable to this issue. This flaw can cause a buffer over-read of 8 bytes, leading to an information disclosure of 7 bytes or a denial of service when the buffer over-read crosses a page boundary. Due to these reasons, this vulnerability has been rated with a moderate severity.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

To mitigate this vulnerability, restrict any custom line terminator string passed to g_io_channel_set_line_term() to a maximum length of one byte before calling g_io_channel_read_line_backend(). Using the default line terminators will completely neutralize this issue.