Cyber Resilience

CVE-2026-59847

Redhat Enterprise Linux 10.0 … 9.0

Published
21 July 2026
Modified
12 August 2026
Patch / advisory
CVSS Score v3.1 5.9
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
EPSS Score 0.0030 23th percentile
Risk Priority 45 floored blend · peak EPSS

Summary

CVE-2026-59847 is a medium-severity Incorrect Check of Function Return Value (CWE-253) vulnerability in Redhat Enterprise Linux. Its CVSS base score is 5.9 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Pre-OS Boot (T1542); ranked at the 23th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SI-2 (Flaw Remediation) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

A flaw was found in libssh. Incorrect AES-GCM finalization checks in builds using the OpenSSL backend can effectively remove integrity protection, allowing an in-path attacker to modify plaintext on the wire without detection.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1542 Pre-OS Boot Stealth
Adversaries may abuse Pre-OS Boot mechanisms as a way to establish persistence on a system.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-59846Same product: Libssh Libssh
CVE-2026-59851Same product: Libssh Libssh
CVE-2026-59849Same product: Libssh Libssh
CVE-2026-15370Same product: Libssh Libssh
CVE-2026-59842Same product: Libssh Libssh
CVE-2026-59844Same product: Libssh Libssh
CVE-2026-59843Same product: Libssh Libssh
CVE-2026-59850Same product: Libssh Libssh
CVE-2026-59845Same product: Libssh Libssh
CVE-2026-59848Same product: Libssh Libssh

Affected Assets

libssh
libssh
all versions
redhat
hardened images
all versions
redhat
enterprise linux
10.0, 8.0, 9.0

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

Requiring flaw remediation and firmware update mechanisms directly ensures ROM code can be patched, eliminating the design weakness.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly enforce proper error-handling and return-value checking during development.

ID.AM-08 partial match
prevents

Life-cycle management encompasses planning for updateability or timely replacement of immutable components.

PR.PS-02 partial match
prevents

Directly requires patching; inability to patch ROM forces reliance on replacement or acceptance of residual risk.

PR.PS-03 partial match
prevents

Addresses hardware that cannot be updated by requiring replacement when security capabilities are lacking.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

Security testing in development catches missing or incorrect return-value checks.

prevents

Secure SDLC mandates return-value checks and error handling, directly reducing CWE-253.

prevents

Application security requirements include robust error handling that mitigates incorrect return-value checks.

prevents

Secure architecture principles require defensive coding practices such as validating function results.

prevents

Secure coding explicitly demands checking return values, covering most of CWE-253.

degrades

Vulnerability management explicitly requires timely patching of firmware/ROM, directly addressing the inability to patch ROM code.

References