How severe is CVE-2026-43618?

CVE-2026-43618 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability high.

Is CVE-2026-43618 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-43618?

CVE-2026-43618 affects Samba Rsync. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-43618?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-43618 have an EU (EUVD) identifier?

Yes. CVE-2026-43618 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-31011.

When was CVE-2026-43618 published?

CVE-2026-43618 was published on 2026-05-20 and last updated on 2026-06-30.

CVE-2026-43618

CVE-2026-43618 is a high-severity vulnerability in Samba Rsync with a CVSS 3.x base score of 8.1. 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-125.

Key facts

Severity: High (CVSS 3.x base score 8.1)
CVSS v4: 6.1
EPSS exploit prediction: 1% (52nd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-31011
Weakness: CWE-125
Affected product: Samba Rsync
Published: 2026-05-20
Last modified: 2026-06-30

Description

Rsync version 3.4.2 and prior contain an integer overflow vulnerability in the compressed-token decoder where a 32-bit signed counter is not checked for overflow, allowing a malicious sender to trigger an overflow that causes the receiver process to read and return data from outside the intended buffer bounds. Attackers can exploit this vulnerability to disclose process memory contents including environment variables, passwords, heap and stack data, and library memory pointers, significantly reducing ASLR effectiveness and facilitating further exploitation.

Frequently asked questions

What is CVE-2026-43618?: Rsync version 3.4.2 and prior contain an integer overflow vulnerability in the compressed-token decoder where a 32-bit signed counter is not checked for overflow, allowing a malicious sender to trigger an overflow that causes the receiver process to read and return data from outside the intended buffer bounds. Attackers can exploit this vulnerability to disclose process memory contents including environment variables, passwords, heap and stack data, and library memory pointers, significantly reducing ASLR effectiveness and facilitating further exploitation.
How severe is CVE-2026-43618?: CVE-2026-43618 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability high.
Is CVE-2026-43618 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-43618?: CVE-2026-43618 affects Samba Rsync. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-43618?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-43618 have an EU (EUVD) identifier?: Yes. CVE-2026-43618 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-31011.
When was CVE-2026-43618 published?: CVE-2026-43618 was published on 2026-05-20 and last updated on 2026-06-30.

References

Affected products (1)

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

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