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CVE-2026-53803— rsync < 3.5.0 Symlink Following Arbitrary File Overwrite

Quick assessment

Affected
RsyncProject rsync
Exploitation
Public or AI PoC available; prioritize validation
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

RsyncProject Rsync是RsyncProject组织开源的一款速度快、功能极其强大的文件复制工具，可用于复制远程文件和本地文件。 RsyncProject Rsync 3.5.0之前版本存在后置链接漏洞，该漏洞源于符号链接跟随问题，攻击者可通过在可预测输出路径（如--log-file、--write-batch或守护进程模式的日志和统计路径）放置符号链接，利用rsync在辅助文件写入时未拒绝符号链接，将输出重定向到任意文件系统位置，导致在rsync以提升权限运行时实现本地权限提升。

CVSS 7.8 · High EPSS 0.23% · P12

Affected Version Matrix 2

VendorProduct Version RangeStatus
RsyncProject rsync ≤ 3.4.4 affected
3.5.0 unaffected
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I. Basic Information for CVE-2026-53803

Vulnerability Information
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Vulnerability Title
rsync < 3.5.0 Symlink Following Arbitrary File Overwrite
Source: CVE Program / CVE List V5
Vulnerability Description
rsync before 3.5.0 contains a symlink following vulnerability that allows local attackers to overwrite arbitrary files by placing a symlink at a predictable output path such as --log-file, --write-batch, or daemon-mode log and statistics paths. Attackers can exploit rsync's failure to reject symlinks during ancillary file writes to redirect output to arbitrary filesystem locations, achieving local privilege escalation on installations where rsync runs with elevated privileges such as setuid or privileged daemon configurations.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Source: CVE Program / CVE List V5
Vulnerability Type
在文件访问前对链接解析不恰当(链接跟随)
Source: CVE Program / CVE List V5
Vulnerability Title
RsyncProject Rsync 后置链接漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
RsyncProject Rsync是RsyncProject组织开源的一款速度快、功能极其强大的文件复制工具，可用于复制远程文件和本地文件。 RsyncProject Rsync 3.5.0之前版本存在后置链接漏洞，该漏洞源于符号链接跟随问题，攻击者可通过在可预测输出路径（如--log-file、--write-batch或守护进程模式的日志和统计路径）放置符号链接，利用rsync在辅助文件写入时未拒绝符号链接，将输出重定向到任意文件系统位置，导致在rsync以提升权限运行时实现本地权限提升。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

Vendor Product Affected Versions CPE Subscribe
RsyncProject rsync 0 ~ 3.4.4 -

II. Public POCs for CVE-2026-53803

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claude_code · 5916 chars
GitHub 复现环境（可 clone 直接跑）
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III. Intelligence Information for CVE-2026-53803

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Vendor Advisories for CVE-2026-53803 (2)

Vendor Pages for CVE-2026-53803 (1)

Same Patch Batch · RsyncProject · 2026-08-13 · 33 CVEs total

CVE-2026-53791 9.1 CRITICAL rsync < 3.5.0 Daemon IP Spoofing via PROXY Protocol Header
CVE-2026-70461 8.2 HIGH rsync 3.2.5 < 3.5.0 Heap Out-of-Bounds Write via files-from Entry
CVE-2026-70456 8.2 HIGH rsync 3.0.1 < 3.5.0 Heap Out-of-Bounds Write via read_args()
CVE-2026-70458 8.2 HIGH rsync 3.0.0 < 3.5.0 Out-of-Bounds Write via FLAG_HLINKED Handling
CVE-2026-53790 8.1 HIGH rsync < 3.5.0 Command Injection via Multiple Code Paths
CVE-2026-70463 8.1 HIGH rsync 3.1.0 < 3.5.0 Authorization Bypass via auth users Directive Parsing
CVE-2026-53795 8.1 HIGH rsync < 3.5.0 Arbitrary File Write via --temp-dir/--link-dest
CVE-2026-53783 8.1 HIGH rsync < 3.5.0 TOCTOU Race Condition Directory Escape via rrsync
CVE-2026-70460 8.1 HIGH rsync 2.3.3 < 3.5.0 Path Traversal via --partial-dir/--backup-dir Symlink
CVE-2026-70454 8.0 HIGH rsync < 3.5.0 TLS Certificate Validation Bypass via SSL/OpenSSL Mode
CVE-2026-70455 7.5 HIGH rsync 3.4.2 < 3.5.0 DoS via --zt Zstandard Compression Thread Exhaustion
CVE-2026-70464 7.5 HIGH rsync 2.0.0 < 3.5.0 Connection Slot Exhaustion DoS via Handshake Stall
CVE-2026-70453 7.5 HIGH rsync < 3.5.0 Algorithmic Complexity DoS via hash_search()
CVE-2026-53793 7.4 HIGH rsync < 3.5.0 Path Confinement Bypass via /./ Boundary Marker in Chroot Mode
CVE-2026-70452 7.4 HIGH rsync 3.1.0 < 3.5.0 Access Control Bypass via DNS Resolution Failure
CVE-2026-53802 7.1 HIGH rsync < 3.5.0 Arbitrary File Read via Symlink Following
CVE-2026-53785 7.1 HIGH rsync < 3.5.0 Path Traversal Write Escape via --relative Mode
CVE-2026-53784 7.1 HIGH rsync < 3.5.0 Path Traversal via Symlink Module Root
CVE-2026-70462 6.5 MEDIUM rsync 3.1.0 < 3.5.0 Signed Integer Overflow via MSG_IO_TIMEOUT
CVE-2026-70457 6.5 MEDIUM rsync 3.2.3 < 3.5.0 Out-of-Bounds Write via parse_size_arg()

Showing top 20 of 33 CVEs. View all on vendor page &rarr; →

IV. Related Vulnerabilities

Same product: rsync
Same vendor: RsyncProject
Same weakness: CWE-59

V. Comments for CVE-2026-53803

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