CVE-2026-70458: CWE-787 Out-of-bounds Write in RsyncProject rsync
rsync 3.0.0 before 3.5.0 contains an out-of-bounds write vulnerability that allows attackers to corrupt memory by triggering HLINK_BUMP processing on file entries with the FLAG_HLINKED flag set while the hard-link preservation option is inactive. Attackers can exploit the missing F_SUM field in the file_struct layout to access memory past the end of the allocated structure, corrupting adjacent heap or stack data.
AI Analysis
Technical Summary
CVE-2026-70458 affects rsync versions from 3.0.0 up to and including 3.4.4. The vulnerability arises from an out-of-bounds write triggered by processing file entries marked with the FLAG_HLINKED flag while the hard-link preservation option is disabled. Specifically, the absence of the F_SUM field in the file_struct layout leads to memory access beyond the allocated structure, causing corruption of adjacent heap or stack memory. This flaw can be exploited remotely without authentication or user interaction, as indicated by the CVSS vector (AV:N/AC:L/PR:N/UI:N). No official patch or remediation guidance is currently documented.
Potential Impact
Successful exploitation of this vulnerability can lead to memory corruption, potentially causing application crashes or arbitrary code execution depending on the context. The vulnerability is remotely exploitable without privileges or user interaction, increasing its risk. However, there are no known exploits in the wild at this time.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, users should consider avoiding processing file entries with the FLAG_HLINKED flag set while hard-link preservation is inactive or apply other vendor-recommended mitigations once published.
CVE-2026-70458: CWE-787 Out-of-bounds Write in RsyncProject rsync
Description
rsync 3.0.0 before 3.5.0 contains an out-of-bounds write vulnerability that allows attackers to corrupt memory by triggering HLINK_BUMP processing on file entries with the FLAG_HLINKED flag set while the hard-link preservation option is inactive. Attackers can exploit the missing F_SUM field in the file_struct layout to access memory past the end of the allocated structure, corrupting adjacent heap or stack data.
CVSS v4.0
Score 8.8high
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-70458 affects rsync versions from 3.0.0 up to and including 3.4.4. The vulnerability arises from an out-of-bounds write triggered by processing file entries marked with the FLAG_HLINKED flag while the hard-link preservation option is disabled. Specifically, the absence of the F_SUM field in the file_struct layout leads to memory access beyond the allocated structure, causing corruption of adjacent heap or stack memory. This flaw can be exploited remotely without authentication or user interaction, as indicated by the CVSS vector (AV:N/AC:L/PR:N/UI:N). No official patch or remediation guidance is currently documented.
Potential Impact
Successful exploitation of this vulnerability can lead to memory corruption, potentially causing application crashes or arbitrary code execution depending on the context. The vulnerability is remotely exploitable without privileges or user interaction, increasing its risk. However, there are no known exploits in the wild at this time.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, users should consider avoiding processing file entries with the FLAG_HLINKED flag set while hard-link preservation is inactive or apply other vendor-recommended mitigations once published.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-08-04T14:52:23.814Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a7ddecabf8831d5395d006b
Added to database: 08/13/2026, 15:12:10 UTC
Last enriched: 08/13/2026, 15:27:26 UTC
Last updated: 08/13/2026, 17:43:31 UTC
Views: 3
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