CVE-2026-7598

Published May 1, 2026

Last updated 3 days ago

CVSS medium 6.9

Overview

Description
A security vulnerability has been detected in libssh2 up to 1.11.1. The impacted element is the function userauth_password of the file src/userauth.c. Such manipulation of the argument username_len/password_len leads to integer overflow. The attack may be launched remotely. The name of the patch is 256d04b60d80bf1190e96b0ad1e91b2174d744b1. A patch should be applied to remediate this issue.
Source
cna@vuldb.com
NVD status
Modified
Products
libssh2

Risk scores

CVSS 4.0

Type
Secondary
Base score
6.9
Impact score
-
Exploitability score
-
Vector string
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Severity
MEDIUM

CVSS 3.1

Type
Primary
Base score
7.3
Impact score
3.4
Exploitability score
3.9
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
Severity
HIGH

CVSS 2.0

Type
Secondary
Base score
7.5
Impact score
6.4
Exploitability score
10
Vector string
AV:N/AC:L/Au:N/C:P/I:P/A:P

Weaknesses

cna@vuldb.com
CWE-189
0b0ca135-0b70-47e7-9f44-1890c2a1c46c
CWE-190

Social media

Hype score
Not currently trending

  1. Fedora has issued security updates for libssh2 and NASM to fix a remotely triggerable heap overflow and arbitrary code execution bugs tracked as CVE-2026-7598 and CVE-2026-6067, according to Fedora Release Engineering changelogs. https://t.co/UlN2tRJ001

    @threatcluster

    7 Jun 2026

    66 Impressions

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Configurations

Related CVEs

  1. libssh2 through 1.11.1 grows its publickey list with SSH2_REALLOC but does not zero-initialize new entries before parsing populates them, so a parse failure reaching the cleanup path leaves libssh2_publickey_list_free operating on an uninitialized entry. A malicious SSH server offering the publickey subsystem can use a malformed response to make cleanup free an uninitialized, attacker-influenceable attrs pointer in a connecting libssh2 client.•CVE-2026-58051
  2. libssh2 through 1.11.1 reads an attacker-controlled 32-bit attribute count from a publickey-subsystem response and uses it in the allocation num_attrs * sizeof(libssh2_publickey_attribute) without bounds checking, so on 32-bit platforms the multiplication overflows to an undersized buffer. A malicious SSH server can then drive the attribute-parsing loop to write past the allocation, causing a heap buffer overflow in a connecting libssh2 client.•CVE-2026-58050
  3. 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.•CVE-2025-15661
  4. libssh2 through 1.11.1, fixed in commit 7acf3df contains an out-of-bounds write vulnerability in ssh2_transport_read() that fails to enforce upper bounds on packet_length field. Remote attackers can send crafted SSH packets with excessively large packet_length values to corrupt heap memory and achieve remote code execution.•CVE-2026-55200
  5. libssh2 through 1.11.1, fixed in commit 1762685, contains a pre-authentication denial of service vulnerability in the SSH_MSG_EXT_INFO handler in src/packet.c that allows a malicious SSH server to cause a client CPU exhaustion loop by sending a crafted extension count value. A malicious server can set nr_extensions to 0xFFFFFFFF during key exchange, causing the client to spin in a tight CPU loop for over 60 seconds because return values from _libssh2_get_string() are unchecked and the session timeout does not apply to CPU-bound loops.•CVE-2026-55199

References

Sources include official advisories and independent security research.