cvedb.io
CVE-2026-53994
HIGH · CVSS 7.5
EPSS exploitation probability: 0%
Published 2026-07-18T20:17:30.283 · Last modified 2026-07-18T20:17:30.283

Summary

ProFTPD mod_sftp contains a heap-based buffer overflow reachable by an authenticated SFTP user. The fxp_packet_read() function accepts the attacker-supplied 32-bit big-endian SFTP packet length without a minimum sanity check. A value of 0 causes an unsigned subtraction elsewhere in the read path to underflow to approximately 4 GB. That oversized request reaches the core memory allocator, where the rounded size is computed in size_t but passed to new_block() as a 32-bit int; the low 32 bits of 0x100000000 are 0, so new_block() returns a small (~512-byte) block while the caller is told it received ~4 GB. The subsequent fill loop then streams attacker-controlled bytes past the end of the 544-byte allocation, producing an attacker-controlled heap buffer overflow. An authenticated user can cras

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.