How severe is CVE-2026-43617?

CVE-2026-43617 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-2026-43617 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (20th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-43617?

CVE-2026-43617 affects Samba Rsync. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-43617?

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

Does CVE-2026-43617 have an EU (EUVD) identifier?

Yes. CVE-2026-43617 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-31013.

When was CVE-2026-43617 published?

CVE-2026-43617 was published on 2026-05-20 and last updated on 2026-06-17.

CVE-2026-43617

CVE-2026-43617 is a medium-severity vulnerability in Samba Rsync 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-289.

Key facts

Severity: Medium (CVSS 3.x base score 4.8)
CVSS v4: 6.3
EPSS exploit prediction: 0% (20th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-31013
Weakness: CWE-289
Affected product: Samba Rsync
Published: 2026-05-20
Last modified: 2026-06-17

Description

Rsync version 3.4.2 and prior contain an authorization bypass vulnerability in the rsync daemon's hostname-based access control list enforcement when configured with chroot. Attackers can bypass hostname-based deny rules by controlling the PTR record for their source IP address, allowing connections from hostnames that administrators intended to deny when reverse DNS resolution fails and defaults to UNKNOWN.

Frequently asked questions

What is CVE-2026-43617?: Rsync version 3.4.2 and prior contain an authorization bypass vulnerability in the rsync daemon's hostname-based access control list enforcement when configured with chroot. Attackers can bypass hostname-based deny rules by controlling the PTR record for their source IP address, allowing connections from hostnames that administrators intended to deny when reverse DNS resolution fails and defaults to UNKNOWN.
How severe is CVE-2026-43617?: CVE-2026-43617 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-2026-43617 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (20th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-43617?: CVE-2026-43617 affects Samba Rsync. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-43617?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-43617 have an EU (EUVD) identifier?: Yes. CVE-2026-43617 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-31013.
When was CVE-2026-43617 published?: CVE-2026-43617 was published on 2026-05-20 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:samba:rsync:*:*:*:*:*:*:*:*

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