libstdc++ buffer overflow on failed bytebybyte writes (DoS/Corruption)
CVE-2026-125709 Published on November 10, 2026
Libstdc++: overflow leaves streambuf in inconsistent state on i/o error.
A flaw was found in libstdc++. When a byte-by-byte write operation fails during file stream processing, the library may still append data into the internal memory buffer. An attacker capable of inducing repeated write failures in an affected service can trigger a buffer overflow, potentially resulting in a Denial of Service (DoS) or memory corruption.
Vulnerability Analysis
CVE-2026-125709 can be exploited with network access, requires user interaction. This vulnerability is consided to have a high level of attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality, with no impact on integrity and availability.
Timeline
Reported to Red Hat.
Made public.
Weakness Type
What is a Memory Corruption Vulnerability?
The software writes data past the end, or before the beginning, of the intended buffer. Typically, this can result in corruption of data, a crash, or code execution. The software may modify an index or perform pointer arithmetic that references a memory location that is outside of the boundaries of the buffer. A subsequent write operation then produces undefined or unexpected results.
CVE-2026-125709 has been classified to as a Memory Corruption vulnerability or weakness.
Products Associated with CVE-2026-125709
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