CVE-2026-70456: CWE-787 Out-of-bounds Write in RsyncProject rsync
An out-of-bounds write vulnerability exists in rsync versions 3.0.1 through 3.4.4 in the read_args() function. This flaw allows a malicious sender to corrupt adjacent heap memory by sending a crafted argument list that causes the argv allocation to be exactly full, resulting in the trailing NULL terminator being written beyond the allocated boundary.
AI Analysis
Technical Summary
CVE-2026-70456 is a high-severity vulnerability in RsyncProject's rsync software affecting versions 3.0.1 up to and including 3.4.4. The issue is an out-of-bounds write in the read_args() function, where a crafted argument list from a malicious sender can cause the trailing NULL terminator to be written one slot beyond the allocated argv array boundary. This heap memory corruption could potentially lead to undefined behavior or exploitation.
Potential Impact
The vulnerability allows remote attackers to corrupt adjacent heap memory without requiring authentication or user interaction. This could lead to denial of service or potentially enable further exploitation depending on the environment and usage of rsync. The CVSS 4.0 base score is 8.8 (high), reflecting its network attack vector, low attack complexity, no privileges required, and high impact on availability.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or patch links are currently provided. Users should monitor RsyncProject advisories for updates and consider restricting access to rsync services from untrusted sources until a fix is available.
CVE-2026-70456: CWE-787 Out-of-bounds Write in RsyncProject rsync
Description
An out-of-bounds write vulnerability exists in rsync versions 3.0.1 through 3.4.4 in the read_args() function. This flaw allows a malicious sender to corrupt adjacent heap memory by sending a crafted argument list that causes the argv allocation to be exactly full, resulting in the trailing NULL terminator being written beyond the allocated boundary.
CVSS v4.0
Score 8.8high
Affected software
RsyncProject
rsync
Run on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-70456 is a high-severity vulnerability in RsyncProject's rsync software affecting versions 3.0.1 up to and including 3.4.4. The issue is an out-of-bounds write in the read_args() function, where a crafted argument list from a malicious sender can cause the trailing NULL terminator to be written one slot beyond the allocated argv array boundary. This heap memory corruption could potentially lead to undefined behavior or exploitation.
Potential Impact
The vulnerability allows remote attackers to corrupt adjacent heap memory without requiring authentication or user interaction. This could lead to denial of service or potentially enable further exploitation depending on the environment and usage of rsync. The CVSS 4.0 base score is 8.8 (high), reflecting its network attack vector, low attack complexity, no privileges required, and high impact on availability.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or patch links are currently provided. Users should monitor RsyncProject advisories for updates and consider restricting access to rsync services from untrusted sources until a fix is available.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-08-04T14:52:23.814Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6a7ddecabf8831d5395d0061
Added to database: 08/13/2026, 15:12:10 UTC
Last enriched: 08/21/2026, 13:41:21 UTC
Last updated: 09/28/2026, 01:47:44 UTC
Views: 43
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.