---
cve: "CVE-2025-15661"
severity: "HIGH"
cvss: 8.3
epss: "1%"
vendor: "libssh2"
kev: false
exploited: false
published: "2026-06-18 21:16:27"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-04T01:17:29+02:00"
---

# CVE-2025-15661

> 8.3 HIGH · 🧪 PoC

## Beschreibung

libssh2 through 1.11.1, fixed in commit 2dae302, contains an out-of-bounds heap read vulnerability in the sftp_symlink() function in src/sftp.c that allows a malicious SSH server or man-in-the-middle attacker to disclose heap memory contents or cause a crash by sending a crafted SSH_FXP_NAME response. Attackers can supply a link_len value larger than the actual packet data in SSH_FXP_NAME responses for SFTP READLINK and REALPATH operations, triggering a heap buffer over-read of up to target_len minus one bytes due to the missing validation of available packet buffer size before the memcpy operation.

## CVSS-Vektor

```
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Hoch | good |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |

## Patch verfügbar (OSV)

- 2dae3024897e1898d389835151f4e9606227721d (Commit)

## Referenzen

- <https://github.com/libssh2/libssh2/pull/1705>
- <https://github.com/libssh2/libssh2/pull/1717>
- <https://github.com/libssh2/libssh2/commit/2dae3024897e1898d389835151f4e9606227721d>
- <https://www.vulncheck.com/advisories/libssh2-heap-buffer-over-read-via-sftp-symlink-in-sftp-c>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2025-15661) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_