How severe is CVE-2026-35388?

CVE-2026-35388 has a CVSS 3.x base score of 2.5, rated low severity. It is exploitable over local access with high attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity low, and availability none.

Is CVE-2026-35388 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (3rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-35388?

CVE-2026-35388 affects Openbsd Openssh. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-35388?

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

Does CVE-2026-35388 have an EU (EUVD) identifier?

Yes. CVE-2026-35388 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-18404.

When was CVE-2026-35388 published?

CVE-2026-35388 was published on 2026-04-02 and last updated on 2026-06-17.

CVE-2026-35388

CVE-2026-35388 is a low-severity vulnerability in Openbsd Openssh with a CVSS 3.x base score of 2.5. 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-420.

Key facts

Severity: Low (CVSS 3.x base score 2.5)
EPSS exploit prediction: 0% (3rd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-18404
Weakness: CWE-420
Affected product: Openbsd Openssh
Published: 2026-04-02
Last modified: 2026-06-17

Description

OpenSSH before 10.3 omits connection multiplexing confirmation for proxy-mode multiplexing sessions.

Frequently asked questions

What is CVE-2026-35388?: OpenSSH before 10.3 omits connection multiplexing confirmation for proxy-mode multiplexing sessions.
How severe is CVE-2026-35388?: CVE-2026-35388 has a CVSS 3.x base score of 2.5, rated low severity. It is exploitable over local access with high attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity low, and availability none.
Is CVE-2026-35388 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (3rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-35388?: CVE-2026-35388 affects Openbsd Openssh. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-35388?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-35388 have an EU (EUVD) identifier?: Yes. CVE-2026-35388 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-18404.
When was CVE-2026-35388 published?: CVE-2026-35388 was published on 2026-04-02 and last updated on 2026-06-17.

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,…
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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…
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CVE-2000-0999 — Critical (CVSS 10.0): Format string vulnerabilities in OpenBSD ssh program (and possibly other BSD-based operating systems) allow attackers…
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Other CWE-420 vulnerabilities

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CVE-2025-13315 — Critical (CVSS 9.8): Twonky Server 8.5.2 on Linux and Windows is vulnerable to an access control flaw. An unauthenticated attacker can…
CVE-2025-54309 — Critical (CVSS 9.0): CrushFTP 10 before 10.8.5 and 11 before 11.3.4_23, when the DMZ proxy feature is not used, mishandles AS2 validation…
CVE-2025-54351 — High (CVSS 8.9): In iperf before 3.19.1, net.c has a buffer overflow when --skip-rx-copy is used (for MSG_TRUNC in recv).
CVE-2026-40217 — High (CVSS 8.8): LiteLLM through 2026-04-08 allows remote attackers to execute arbitrary code via bytecode rewriting at the…

Browse all CWE-420 vulnerabilities →

Threat intelligence

Threat-intel indicators referencing this CVE:

152.32.208.73 (ipv4-addr)
152.32.217.163 (ipv4-addr)
152.32.204.21 (ipv4-addr)
152.32.145.49 (ipv4-addr)
104.218.164.192 (ipv4-addr)
165.154.162.193 (ipv4-addr)
165.154.11.210 (ipv4-addr)
152.32.207.42 (ipv4-addr)