Cyber Resilience

CVE-2026-45232

Samba Rsync ≤ 3.4.3

Public PoC
Published
20 May 2026
Modified
24 July 2026
Patch / advisory
View advisory
CVSS Score v4 2.1
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0034 26th percentile
Risk Priority 15 floored blend · peak EPSS

Summary

CVE-2026-45232 is a low-severity Off-by-one Error (CWE-193) vulnerability in Samba Rsync. Its CVSS base score is 2.1 (Low).

Operationally, ranked at the 26th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to SI-2 (Flaw Remediation) and RA-5 (Vulnerability Monitoring and Scanning) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

Rsync versions before 3.4.3 contain an off-by-one out-of-bounds stack write vulnerability in the establish_proxy_connection() function in socket.c that allows network attackers to corrupt stack memory by sending a malformed HTTP proxy response. Attackers can exploit this by positioning themselves between…

more

the client and proxy or controlling the proxy server to send a response line of 1023 or more bytes without a newline terminator, causing a null byte to be written to an out-of-bounds stack address when the RSYNC_PROXY environment variable is set.

CWE(s)
CWE-193

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

Insufficient information to map techniques.
Confidence: LOW · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-43619Same product: Samba Rsync
CVE-2026-43617Same product: Samba Rsync
CVE-2026-43620Same product: Samba Rsync
CVE-2026-41035Same product: Samba Rsync
CVE-2026-29518Same product: Samba Rsync
CVE-2026-43618Same product: Samba Rsync
CVE-2025-0620Same vendor: Samba
CVE-2023-0225Same vendor: Samba
CVE-2023-0614Same vendor: Samba
CVE-2023-5568Same vendor: Samba

Affected Assets

samba
rsync
≤ 3.4.3

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • SI-2 Flaw Remediation
  • SC-7 Boundary Protection
Detect
Catch it (NIST detect / respond)
  • RA-5 Vulnerability Monitoring and Scanning
Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V6.2.1

Mitigating Controls (NIST 800-53 r5) AI

SI-2 Flaw Remediation good match
prevent

Directly requires timely patching or upgrading of rsync to version 3.4.3+ to eliminate the off-by-one flaw in establish_proxy_connection().

SC-7 Boundary Protection partial match
prevent

Boundary protection at network egress points can block an attacker positioned between the rsync client and an untrusted HTTP proxy from supplying the malformed 1023-byte response.

RA-5 Vulnerability Monitoring and Scanning partial match
detect

Regular vulnerability scanning can identify installations of rsync < 3.4.3 that remain exposed when RSYNC_PROXY is set.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly prevent off-by-one errors via reviews, static analysis, and testing.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
detects

Security testing in development and acceptance can detect off-by-one errors before release.

A.8.25 Secure development life cycle partial match
prevents

Secure development life cycle includes requirements and reviews that can catch off-by-one errors.

A.8.26 Application security requirements partial match
prevents

Application security requirements can specify bounds-checking and input validation to prevent off-by-one errors.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure system architecture and engineering principles promote defensive coding practices that reduce off-by-one mistakes.

A.8.28 Secure coding partial match
prevents

Secure coding directly addresses off-by-one errors through coding standards and peer review.

References