CVE-2026-43620
CVE-2026-43620 is a medium-severity vulnerability in Samba Rsync with a CVSS 3.x base score of 6.5. 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-125.
Key facts
- Severity: Medium (CVSS 3.x base score 6.5)
- CVSS v4: 6.9
- EPSS exploit prediction: 1% (39th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-31012
- Weakness: CWE-125
- Affected product: Samba Rsync
- Published:
- Last modified:
Description
Rsync version 3.4.2 and prior contain a receiver-side out-of-bounds array read vulnerability in recv_files() in receiver.c that allows a malicious rsync server to crash the rsync client process. Attackers can exploit the vulnerability by setting CF_INC_RECURSE in compatibility flags and sending a specially crafted file list where the first sorted entry is not the leading dot directory, followed by a transfer record with ndx=0 and an iflag word without ITEM_TRANSFER, causing the receiver to read 8 bytes before the allocated pointer array and dereference an invalid pointer at an unmapped address, resulting in a deterministic SIGSEGV crash of the rsync client.
Frequently asked questions
- What is CVE-2026-43620?
- Rsync version 3.4.2 and prior contain a receiver-side out-of-bounds array read vulnerability in recv_files() in receiver.c that allows a malicious rsync server to crash the rsync client process. Attackers can exploit the vulnerability by setting CF_INC_RECURSE in compatibility flags and sending a specially crafted file list where the first sorted entry is not the leading dot directory, followed by a transfer record with ndx=0 and an iflag word without ITEM_TRANSFER, causing the receiver to read 8 bytes before the allocated pointer array and dereference an invalid pointer at an unmapped address, resulting in a deterministic SIGSEGV crash of the rsync client.
- How severe is CVE-2026-43620?
- CVE-2026-43620 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.
- Is CVE-2026-43620 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (39th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2026-43620?
- CVE-2026-43620 affects Samba Rsync. See the affected-products list for the exact vulnerable versions.
- How do I fix CVE-2026-43620?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
- Does CVE-2026-43620 have an EU (EUVD) identifier?
- Yes. CVE-2026-43620 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-31012.
- When was CVE-2026-43620 published?
- CVE-2026-43620 was published on 2026-05-20 and last updated on 2026-06-17.
References
- https://github.com/RsyncProject/rsync/releases/tag/v3.4.3
- https://github.com/RsyncProject/rsync/security/advisories/GHSA-28pw-r563-rxvm
- https://www.vulncheck.com/advisories/rsync-out-of-bounds-array-read-via-recv-files
Affected products (1)
- cpe:2.3:a:samba:rsync:*:*:*:*:*:*:*:*
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