CVE-2026-70458
Description
A flaw was found in rsync. This out-of-bounds write vulnerability allows attackers to corrupt memory by triggering specific processing on specially crafted file entries when hard-link preservation is not active. This can lead to denial of service or other unpredictable system behavior.
Statement
This Important out-of-bounds write vulnerability in rsync can lead to memory corruption when processing specially crafted file entries, potentially resulting in a denial of service. The flaw is triggered when hard-link preservation is inactive, allowing a remote attacker to exploit it without requiring user interaction or elevated privileges.
Mitigation
Disable the rsyncd daemon if unused (systemctl disable --now rsyncd), or strictly limit TCP/873 access to trusted clients via firewall rules. For daemons that must remain active, explicitly set refuse options = checksum in rsyncd.conf to block the demonstrated out-of-bounds write vector. Finally, when operating as a client pulling from untrusted peers, always append the --hard-links (-H) flag to force safe memory allocation and prevent corruption.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 8.2 | N/A | 8.2 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | Low | N/A | Low |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H
Understanding the Weakness (CWE)
Integrity
Technical Impact: Modify Memory; Execute Unauthorized Code or Commands
Write operations could cause memory corruption. In some cases, an adversary can modify control data such as return addresses in order to execute unexpected code.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
Attempting to access out-of-range, invalid, or unauthorized memory could cause the product to crash.
Other
Technical Impact: Unexpected State
Subsequent write operations can produce undefined or unexpected results.
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