Is CVE-2026-59844 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-59844 being exploited in the wild.

How severe is CVE-2026-59844?

Medium severity, with a CVSS score of 6.5, published 21 July 2026.

Is there a fix for CVE-2026-59844?

No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

How is CVE-2026-59844 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-59844?

Check whether you run Libssh, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8 or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-59844: libssh denial of service via oversized SFTP read length

CVE-2026-59844 · Severity: medium · CVSS 6.5 · Published 2026-07-21

A vulnerability in the libssh library, which provides secure communication for applications, could allow a user with valid login credentials to crash the server. By sending specially crafted file transfer requests with extremely large size values, an attacker can force the server to consume all available memory. This results in a denial of service, preventing legitimate users from accessing the system or its services.

Technologies: Libssh, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9. Vendors: Libssh, Red Hat.

Quick answers

Is CVE-2026-59844 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-59844 being exploited in the wild.
How severe is CVE-2026-59844?: Medium severity, with a CVSS score of 6.5, published 21 July 2026.
Which products and versions are affected?: Libssh unspecified.
Is there a fix for CVE-2026-59844?: No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-59844 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-59844?: Check whether you run Libssh, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8 or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A memory allocation vulnerability (CWE-789) exists in the libssh SFTP server implementation, specifically within the sftp_make_client_message() function and the process_read() path in src/sftpserver.c. The server fails to enforce an upper bound on the 'len' field provided in SSH_FXP_READ requests. An authenticated remote attacker can exploit this by sending requests with an arbitrarily large length, forcing the server to allocate excessive memory. Repeated requests can lead to memory exhaustion and a denial of service (DoS) condition.

Affected products

libssh libssh unspecified
Red Hat Red Hat Enterprise Linux 8
Red Hat Red Hat Enterprise Linux 9
Red Hat Red Hat Enterprise Linux 10

Timeline

2026-07-08: other: Reported to Red Hat Bugzilla
2026-07-21: advisory: NVD publication date

References

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