How severe is GHSA-55r9-5mx9-qq7r?

GHSA-55r9-5mx9-qq7r has a CVSS score of 4.3/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by GHSA-55r9-5mx9-qq7r?

GHSA-55r9-5mx9-qq7r affects the following packages: zotregistry.io/zot (Go), zotregistry.dev/zot (Go). Ecosystems affected: Go.

How do I fix GHSA-55r9-5mx9-qq7r?

Update zotregistry.io/zot to 2.1.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-55r9-5mx9-qq7r is resolved across your whole dependency graph.

How do I detect GHSA-55r9-5mx9-qq7r in my Go dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for zotregistry.io/zot. 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.

How do I mitigate GHSA-55r9-5mx9-qq7r if there is no patch (or I can't update yet)?

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.

How does O3 Security protect against GHSA-55r9-5mx9-qq7r?

O3 pinpoints whether GHSA-55r9-5mx9-qq7r is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is GHSA-55r9-5mx9-qq7r actively exploited in the wild?

No public exploit code has been indexed for GHSA-55r9-5mx9-qq7r 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 GHSA-55r9-5mx9-qq7r?

GHSA-55r9-5mx9-qq7r has an EPSS (Exploit Prediction Scoring System) score of 0.3%, placing it in the 22th 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 GHSA-55r9-5mx9-qq7r?

GHSA-55r9-5mx9-qq7r is classified as CWE-639 (CWE-639). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-55r9-5mx9-qq7r published, and has it been updated?

GHSA-55r9-5mx9-qq7r was published on July 9, 2024 and was last updated on February 4, 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

GHSA-55r9-5mx9-qq7r

MEDIUM

Cache driver GetBlob() allows read access to any blob without access control check

Also known asCVE-2024-39897GO-2024-2979

Published

Jul 9, 2024

Updated

Feb 4, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

EPSS Exploitation Probability

via FIRST.org ↗

0.3%probability of exploitation in next 30 days

Lower Risk22th percentile-0.06%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

2 pkgs affected

🐹zotregistry.io/zot🐹zotregistry.dev/zot

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

Cache driver GetBlob() allows read access to any blob without access control check

Details

If a Zot accessControl policy allows users read access to some repositories but restricts read access to other repositories and dedupe is enabled (it is enabled by default), then an attacker who knows the name of an image and the digest of a blob (that they do not have read access to), they may maliciously read it via a second repository they do have read access to. This allows an attacker to read an image that the accessControl policy denies.

This attack is possible because ImageStore.CheckBlob() calls checkCacheBlob() to find the blob a global cache by searching for the digest. If it is found, it is copied to the user requested repository with copyBlob().

This cache behavior is intentionally used in RouteHandler.CreateBlobUpload() to implement cross repository blob mount (POST /v2/<name>/blobs/uploads/?mount=<digest>&from=<repository name>) in Zot. This is still missing an access control to check read access on the source repository.

This cache behavior is unexpectedly also used in RouteHandler.CheckBlob() too for HEAD /v2/<name>/blobs/<digest>. If a blob is requested that does not exist on the requested repository, Zot will search for it in a global cache (possibly returning a result from an from an incorrect repository) and then will store it into the ImageStore for the requested repository.

RouteHandler.GetBlob() does not call ImageStore.CheckBlob() so it is not directly vulnerable. However an attacker with only limited read access may first call CheckBlob() to fetch the blob from the cache, then call GetBlob() to read the blob.

Mitigation

The attack may be mitigated by configuring "dedupe": false in the "storage" settings. This disables Zot's cache drivers. dedupe is enabled by default using the BoltDB cache driver.

Impact

An attacker can read images that the accessControl policy denies if they have read access to any other second repository.

This attack only allows accessing blobs (both config and layers) by digest. Manifests cannot be accessed.

This attack requires the attacker to know the name of a private image and its layer digests. A scenario where this might happen is if a project has public CI build logs but publishes the image to a private repository. Many image build tools log layer digests.

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`zotregistry.io/zot`	all versions	2.1.0
🐹Go	`zotregistry.dev/zot`	all versions	2.1.0

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for zotregistry.io/zot. 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.
Fix
Update zotregistry.io/zot to 2.1.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-55r9-5mx9-qq7r is resolved across your whole dependency graph.
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.
How O3 protects you
O3 pinpoints whether GHSA-55r9-5mx9-qq7r 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-55r9-5mx9-qq7r. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Summary Cache driver `GetBlob()` allows read access to any blob without access control check ### Details If a Zot `accessControl` policy allows users read access to some repositories but restricts read access to other repositories and `dedupe` is enabled (it is enabled by default), then an attacker who knows the name of an image and the digest of a blob (that they do not have read access to), they may maliciously read it via a second repository they do have read access to. This allows an attacker to read an image that the `accessControl` policy denies. This attack is possible because [

O3 Security · Impact-Aware SCA

Is GHSA-55r9-5mx9-qq7r in your dependencies?

O3 detects GHSA-55r9-5mx9-qq7r across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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