How severe is CVE-2026-49980?

CVE-2026-49980 has a CVSS score of 9.8/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2026-49980?

CVE-2026-49980 affects the following packages: github.com/rclone/rclone (Go). Ecosystems affected: Go.

How do I fix CVE-2026-49980?

Update github.com/rclone/rclone to 1.74.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-49980 is resolved across your whole dependency graph.

How do I detect CVE-2026-49980 in my Go dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/rclone/rclone, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-49980 if there is no patch (or I can't update yet)?

Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.

Is CVE-2026-49980 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-49980 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-49980?

CVE-2026-49980 has an EPSS (Exploit Prediction Scoring System) score of 0.8%, placing it in the 54th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-49980?

CVE-2026-49980 is classified as Missing Authentication (CWE-306), OS Command Injection (CWE-78). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2026-49980 published, and has it been updated?

CVE-2026-49980 was published on June 24, 2026 and was last updated on September 9, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐹

🐹 Go

Not in CISA KEV

CRITICAL severity

CVE-2026-49980 — rclone

CRITICAL

CVE-2026-49980 is a critical-severity (CVSS 9.8) Missing Authentication vulnerability in github.com/rclone/rclone. A fix is available for github.com/rclone/rclone — see the affected versions and patch details below.

Rclone: Unauthenticated command execution in `rclone rcd --rc-serve` via inline remote instantiation, bypassing CVE-2026-41179 fix

Also known asBIT-rclone-2026-49980GHSA-qw24-gh76-8rvvGO-2026-5596

Published

Jun 24, 2026

Updated

Sep 9, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Sep 26, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
A successful exploit gives an attacker total control of the affected component, not partial access.
CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-49980.

EPSS Exploitation Probability

via FIRST.org ↗

0.8%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs54th percentile — riskier than 54% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2026-49980 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 379,842 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

1 pkg affected

🐹github.com/rclone/rclone

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

Summary

rclone rcd --rc-serve accepts unauthenticated GET and HEAD requests to paths of the form:

/[remote:path]/object

The remote value is parsed from the URL and passed to normal backend initialization. Inline remote configuration can set backend options that execute local commands during initialization. As a result, a single unauthenticated GET or HEAD request can execute a command as the rclone process user.

Versions from 1.55.0 onwards are vulnerable to command execution. Earlier versions (from 1.46.0) are vulnerable to the unauthenticated local file read described under "Additional impact" but not to command execution, because inline backend option overrides did not exist until 1.55.0.

Preconditions

Preconditions for this vulnerability are:

The rclone remote control API must be enabled, either by the --rc flag or by running the rclone rcd server
The remote control API must be reachable by the attacker - by default rclone only serves the rc to localhost unless the --rc-addr flag is in use
The rc must have been deployed without global RC HTTP authentication - so not using --rc-user/--rc-pass/--rc-htpasswd/etc
The --rc-serve flag must be in use

Impact

An unauthenticated network attacker who can reach the RC HTTP listener can execute commands as the rclone process user.

Additional impact observed during testing:

GET and HEAD both trigger backend initialization.
The same path allows unauthenticated local file read through inline local remotes.
Inline global.* options can mutate process-wide rclone configuration, including global.http_proxy.
Browser subresource requests can also trigger the issue against a localhost-only RC listener. In testing, Firefox triggered the payload from a public HTTPS page containing only an <img> tag pointing at http://127.0.0.1:5572/.... This is an additional impact multiplier, not the primary attack precondition.

Mitigations / Workarounds

Upgrade to rclone 1.74.3 (or 1.75.0 when released).
Or, configure HTTP authentication on the rc with --rc-user/--rc-pass or --rc-htpasswd, which has always been the recommended deployment.
Or, do not use --rc-serve if file serving is not needed.

The Fix

The vulnerabilities in this advisory have been fixed by two commits:

rc: fix unauthenticated command execution via --rc-serve inline remotes
rc: stop global.* connection string options changing config

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/rclone/rclone`	≥ 1.46.0&&< 1.74.3	1.74.3`go get github.com/rclone/rclone@v1.74.3`

Affected Products

1 product · 1 configurations

Application

rclonerclone

≥ 1.46 && < 1.74.3

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/rclone/rclone, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/rclone/rclone to 1.74.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-49980 is resolved across your whole dependency graph.
Workarounds
Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatImportant

OpenShift API for Data Protection (OADP) and Red Hat Advanced Cluster Management for Kubernetes (RHACM) do not run rclone rcd --rc-serve with an unauthenticated RC listener. OADP relies on Restic (rclone serve restic --stdio) and Kopia (WebDAV serve with RC authentication), while RHACM VolSync uses rclone sync/copy or…

Workaround published by Red Hat

Until upgraded: 1. Stop using --rc-serve 2. Add RC auth (--rc-user + --rc-pass or --rc-htpasswd), and 3. Keep RC on localhost only (do not bind 0.0.0.0 without auth)

Source: Red Hat security advisory for CVE-2026-49980 (CC BY 4.0)

Frequently Asked Questions

## Summary `rclone rcd --rc-serve` accepts unauthenticated `GET` and `HEAD` requests to paths of the form: ```text /[remote:path]/object ``` The `remote` value is parsed from the URL and passed to normal backend initialization. Inline remote configuration can set backend options that execute local commands during initialization. As a result, a single unauthenticated `GET` or `HEAD` request can execute a command as the rclone process user. Versions from 1.55.0 onwards are vulnerable to command execution. Earlier versions (from 1.46.0) are vulnerable to the unauthenticated local file read de