Heap-based Buffer Overflow Affecting proftpd/proftpd package, versions [,1.3.9a)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Start learning- Snyk IDSNYK-UNMANAGED-PROFTPDPROFTPD-18017816
- published19 Jul 2026
- disclosed18 Jul 2026
- creditUnknown
Introduced: 18 Jul 2026
NewCVE-2026-53994 (opens in a new tab)How to fix?
Upgrade proftpd/proftpd to version 1.3.9a or higher.
Overview
Affected versions of this package are vulnerable to Heap-based Buffer Overflow in the fxp_packet_read function when processing attacker-supplied SFTP packet lengths without proper minimum sanity checks. An attacker can cause a heap buffer overflow by sending a specially crafted SFTP packet with a length of 0, leading to an unsigned integer underflow and size truncation, which results in writing attacker-controlled data beyond the allocated memory. This can allow crashing the per-connection session or potentially corrupting heap metadata by sending a malformed packet after authentication.