How severe is CVE-2026-59998?

CVE-2026-59998 has a CVSS 3.x base score of 4.8, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2026-59998 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (8th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-59998?

CVE-2026-59998 affects Openbsd Openssh. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-59998?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2026-59998 published?

CVE-2026-59998 was published on 2026-07-08 and last updated on 2026-07-09.

CVE-2026-59998

CVE-2026-59998 is a medium-severity vulnerability in Openbsd Openssh with a CVSS 3.x base score of 4.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-573.

Key facts

Severity: Medium (CVSS 3.x base score 4.8)
EPSS exploit prediction: 0% (8th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-573
Affected product: Openbsd Openssh
Published: 2026-07-08
Last modified: 2026-07-09

Description

sshd in OpenSSH before 10.4 has an undocumented security-relevant behavior: GSSAPIStrictAcceptorCheck has no value if the server is in Windows Active Directory.

Frequently asked questions

What is CVE-2026-59998?: sshd in OpenSSH before 10.4 has an undocumented security-relevant behavior: GSSAPIStrictAcceptorCheck has no value if the server is in Windows Active Directory.
How severe is CVE-2026-59998?: CVE-2026-59998 has a CVSS 3.x base score of 4.8, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2026-59998 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (8th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-59998?: CVE-2026-59998 affects Openbsd Openssh. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-59998?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2026-59998 published?: CVE-2026-59998 was published on 2026-07-08 and last updated on 2026-07-09.

References

Affected products (1)

cpe:2.3:a:openbsd:openssh:*:*:*:*:*:*:*:*

More vulnerabilities in Openbsd Openssh

CVE-2003-0786 — Critical (CVSS 10.0): The SSH1 PAM challenge response authentication in OpenSSH 3.7.1 and 3.7.1p1, when Privilege Separation is disabled,…
CVE-2003-0693 — Critical (CVSS 10.0): A "buffer management error" in buffer_append_space of buffer.c for OpenSSH before 3.7 may allow remote attackers to…
CVE-2002-0640 — Critical (CVSS 10.0): Buffer overflow in sshd in OpenSSH 2.3.1 through 3.3 may allow remote attackers to execute arbitrary code via a large…
CVE-2001-0144 — Critical (CVSS 10.0): CORE SDI SSH1 CRC-32 compensation attack detector allows remote attackers to execute arbitrary commands on an SSH…
CVE-2000-0999 — Critical (CVSS 10.0): Format string vulnerabilities in OpenBSD ssh program (and possibly other BSD-based operating systems) allow attackers…
CVE-2000-0525 — Critical (CVSS 10.0): OpenSSH does not properly drop privileges when the UseLogin option is enabled, which allows local users to execute…

All CVEs affecting Openbsd Openssh →

Other CWE-573 vulnerabilities

CVE-2026-41583 — Critical (CVSS 9.1): ZEBRA is a Zcash node written entirely in Rust. Prior to zebrad version 4.3.1 and prior to zebra-script version 5.0.2,…
CVE-2025-21601 — High (CVSS 7.5): An Improper Following of Specification by Caller vulnerability in web management (J-Web, Captive Portal, 802.1X,…
CVE-2026-89087 — High (CVSS 7.3): The cstruct package before 6.3.0 for OCaml mishandles indexes.
CVE-2025-69287 — Medium (CVSS 5.4): The BSV Blockchain SDK is a unified TypeScript SDK for developing scalable apps on the BSV Blockchain. Prior to version…
CVE-2019-14829 — Medium (CVSS 4.3): A vulnerability was found in Moodle affection 3.7 to 3.7.1, 3.6 to 3.6.5, 3.5 to 3.5.7 and earlier unsupported versions…
CVE-2025-46330 — Low (CVSS 3.3): libsnowflakeclient is the Snowflake Connector for C/C++. Versions starting from 0.5.0 to before 2.2.0, incorrectly…

Browse all CWE-573 vulnerabilities →

Threat intelligence

Threat-intel indicators referencing this CVE:

118.193.56.184 (ipv4-addr)
101.36.114.124 (ipv4-addr)
152.32.149.19 (ipv4-addr)
165.22.134.80 (ipv4-addr)
172.174.212.111 (ipv4-addr)
43.157.27.211 (ipv4-addr)
112.124.67.212 (ipv4-addr)
121.43.116.1 (ipv4-addr)