CVE-2026-77014: Numeric Truncation Error in Red Hat Red Hat Enterprise Linux 10

The vulnerability exists in libsoup's SoupServer component used in Red Hat Enterprise Linux 10, specifically in the sort_ranges() comparator function within soup-message-headers.c. The function truncates a 64-bit subtraction result to a 32-bit int, causing incorrect sign flipping when range offsets differ by more than INT_MAX. This results in the server silently omitting requested byte ranges from HTTP 206 Partial Content responses when serving resources larger than about 2 GB. The flaw impacts integrity by modifying memory content returned to clients. Exploitation requires the server to serve large resources and can be triggered remotely without authentication or user interaction. Red Hat has not provided a fix or mitigation for this issue as of the advisory date.

The vulnerability allows a remote attacker to cause the server to silently omit requested byte ranges in HTTP 206 Partial Content responses, affecting the integrity of the data served. There is no impact on confidentiality or availability. The impact is limited by the requirement that the server must serve resources larger than approximately 2 GB. The flaw does not allow code execution or denial of service but may cause clients to receive incomplete data without indication.

According to the Red Hat advisory, no mitigation is currently available for this vulnerability. Users should monitor the Red Hat advisory page for updates on patches or fixes. Since no workaround exists, affected systems should be evaluated for exposure to large resource serving scenarios and consider risk accordingly.