Your RSA-2048 keys break in 2030. Find every one of them before attackers do.
🐹
🐹 Go
Not in CISA KEV
MEDIUM severity

GHSA-fh74-hm69-rqjw

MEDIUMFix: opencontainers/runc#2190

GHSA-fh74-hm69-rqjw is a medium-severity (CVSS 5.9) CWE-706 vulnerability in github.com/opencontainers/runc. O3 Security confirms whether GHSA-fh74-hm69-rqjw is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

opencontainers runc contains procfs race condition with a shared volume mount

Also known asCVE-2019-19921GO-2021-0087
Published
May 27, 2021
Updated
Feb 4, 2026
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Feb 4, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Real-World Exposure

1 pkg affected
🐹github.com/opencontainers/runc

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

Impact

By crafting a malicious root filesystem (with /proc being a symlink to a directory which was inside a volume shared with another running container), an attacker in control of both containers can trick runc into not correctly configuring the container's security labels and not correctly masking paths inside /proc which contain potentially-sensitive information about the host (or even allow for direct attacks against the host).

In order to exploit this bug, an untrusted user must be able to spawn custom containers with custom mount configurations (such that a volume is shared between two containers). It should be noted that we consider this to be a fairly high level of access for an untrusted user -- and we do not recommend allowing completely untrusted users to have such degrees of access without further restrictions.

Specific Go Package Affected

github.com/opencontainers/runc/libcontainer

Patches

This vulnerability has been fixed in 1.0.0-rc10. It should be noted that the current fix is effectively a hot-fix, and there are known ways for it to be worked around (such as making the entire root filesystem a shared volume controlled by another container). We recommend that users review their access policies to ensure that untrusted users do not have such high levels of controls over container mount configuration.

Workarounds

If you are not providing the ability for untrusted users to configure mountpoints for runc (or through a higher-level tool such as docker run -v) then you are not vulnerable to this issue. This exploit requires fairly complicated levels of access (which are available for some public clouds but are not necessarily available for all deployments).

Additionally, it appears as though it is not possible to exploit this vulnerability through Docker (due to the order of mounts Docker generates). However you should not depend on this, as it may be possible to work around this roadblock.

Credits

This vulnerability was discovered by Cure53, as part of a third-party security audit.

For more information

If you have any questions or comments about this advisory:

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🐹Gogithub.com/opencontainers/runcall versions1.0.0-rc9.0.20200122160610-2fc03cc11c77

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/opencontainers/runc. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

  2. Fix

    Update github.com/opencontainers/runc to 1.0.0-rc9.0.20200122160610-2fc03cc11c77 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-fh74-hm69-rqjw is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

  4. How O3 protects you

    O3 pinpoints whether GHSA-fh74-hm69-rqjw is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-fh74-hm69-rqjw. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

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 HatModerate

For Red Hat OpenStack Platform, because runc is not directly used by the director-operator, no update will be provided at this time for the operator containers.

Frequently Asked Questions

### Impact By crafting a malicious root filesystem (with `/proc` being a symlink to a directory which was inside a volume shared with another running container), an attacker in control of both containers can trick `runc` into not correctly configuring the container's security labels and not correctly masking paths inside `/proc` which contain potentially-sensitive information about the host (or even allow for direct attacks against the host). In order to exploit this bug, an untrusted user must be able to spawn custom containers with custom mount configurations (such that a volume is shared b
O3 Security · Impact-Aware SCA

Is GHSA-fh74-hm69-rqjw in your dependencies?

O3 detects GHSA-fh74-hm69-rqjw across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

GHSA-fh74-hm69-rqjw: runc (Medium 5.9) | O3 Security