How severe is CVE-2026-3731?

CVE-2026-3731 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.

Is CVE-2026-3731 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (46th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-3731?

CVE-2026-3731 affects Libssh. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-3731?

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

Does CVE-2026-3731 have an EU (EUVD) identifier?

Yes. CVE-2026-3731 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-10234.

When was CVE-2026-3731 published?

CVE-2026-3731 was published on 2026-03-08 and last updated on 2026-06-17.

CVE-2026-3731

CVE-2026-3731 is a medium-severity vulnerability in Libssh with a CVSS 3.x base score of 5.3. 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-119.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
CVSS v2: 5.0
CVSS v4: 6.9
EPSS exploit prediction: 1% (46th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-10234
Weakness: CWE-119
Affected product: Libssh
Published: 2026-03-08
Last modified: 2026-06-17

Description

A weakness has been identified in libssh up to 0.11.3. The impacted element is the function sftp_extensions_get_name/sftp_extensions_get_data of the file src/sftp.c of the component SFTP Extension Name Handler. Executing a manipulation of the argument idx can lead to out-of-bounds read. The attack may be performed from remote. Upgrading to version 0.11.4 and 0.12.0 is sufficient to resolve this issue. This patch is called 855a0853ad3abd4a6cd85ce06fce6d8d4c7a0b60. You should upgrade the affected component.

Frequently asked questions

What is CVE-2026-3731?: A weakness has been identified in libssh up to 0.11.3. The impacted element is the function sftp_extensions_get_name/sftp_extensions_get_data of the file src/sftp.c of the component SFTP Extension Name Handler. Executing a manipulation of the argument idx can lead to out-of-bounds read. The attack may be performed from remote. Upgrading to version 0.11.4 and 0.12.0 is sufficient to resolve this issue. This patch is called 855a0853ad3abd4a6cd85ce06fce6d8d4c7a0b60. You should upgrade the affected component.
How severe is CVE-2026-3731?: CVE-2026-3731 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.
Is CVE-2026-3731 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (46th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-3731?: CVE-2026-3731 affects Libssh. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-3731?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-3731 have an EU (EUVD) identifier?: Yes. CVE-2026-3731 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-10234.
When was CVE-2026-3731 published?: CVE-2026-3731 was published on 2026-03-08 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:libssh:libssh:*:*:*:*:*:*:*:*

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