How severe is GHSA-c4qc-4q9p-m9q9?

No CVSS score has been assigned to GHSA-c4qc-4q9p-m9q9 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-c4qc-4q9p-m9q9?

GHSA-c4qc-4q9p-m9q9 affects the following packages: org.apache.shiro:shiro-core (Maven). Ecosystems affected: Maven.

How do I fix GHSA-c4qc-4q9p-m9q9?

Update org.apache.shiro:shiro-core to 2.1.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-c4qc-4q9p-m9q9 is resolved across your whole dependency graph.

How do I detect GHSA-c4qc-4q9p-m9q9 in my Maven dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.shiro:shiro-core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate GHSA-c4qc-4q9p-m9q9 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-c4qc-4q9p-m9q9?

O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-c4qc-4q9p-m9q9 can be triaged on real exposure rather than presence alone.

Is GHSA-c4qc-4q9p-m9q9 actively exploited in the wild?

No public exploit code has been indexed for GHSA-c4qc-4q9p-m9q9 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-c4qc-4q9p-m9q9?

GHSA-c4qc-4q9p-m9q9 has an EPSS (Exploit Prediction Scoring System) score of 0.2%, placing it in the 13th 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-c4qc-4q9p-m9q9?

GHSA-c4qc-4q9p-m9q9 is classified as CWE-208 (CWE-208). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-c4qc-4q9p-m9q9 published, and has it been updated?

GHSA-c4qc-4q9p-m9q9 was published on February 10, 2026 and was last updated on September 10, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

☕ Maven

Not in CISA KEV

GHSA-c4qc-4q9p-m9q9 — shiro-core

GHSA-c4qc-4q9p-m9q9 is a CWE-208 vulnerability in org.apache.shiro:shiro-core. A fix is available for org.apache.shiro:shiro-core — see the affected versions and patch details below.

Apache Shiro Affected by an Observable Timing Discrepancy Vulnerability

Also known asCVE-2026-23901

Published

Feb 10, 2026

Updated

Sep 10, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Sep 21, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

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 GHSA-c4qc-4q9p-m9q9.

EPSS Exploitation Probability

via FIRST.org ↗

0.2%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs13th percentile — riskier than 13% of all scored CVEsHighest risk

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.

Real-World Exposure

1 pkg affected

☕org.apache.shiro:shiro-core

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

Description

Observable Timing Discrepancy vulnerability in Apache Shiro.

This issue affects Apache Shiro: from 1., 2. before 2.0.7.

Users are recommended to upgrade to version 2.0.7 or later, which fixes the issue.

Prior to Shiro 2.0.7, code paths for non-existent vs. existing users are different enough, that a brute-force attack may be able to tell, by timing the requests only, determine if the request failed because of a non-existent user vs. wrong password.

The most likely attack vector is a local attack only. Shiro security model https://shiro.apache.org/security-model.html#username_enumeration discusses this as well.

Typically, brute force attack can be mitigated at the infrastructure level.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`org.apache.shiro:shiro-core`	all versions	2.1.0`org.apache.shiro:shiro-core: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 org.apache.shiro:shiro-core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.apache.shiro:shiro-core to 2.1.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-c4qc-4q9p-m9q9 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-c4qc-4q9p-m9q9 can be triaged on real exposure rather than presence alone.

Tailored to GHSA-c4qc-4q9p-m9q9. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

Observable Timing Discrepancy vulnerability in Apache Shiro. This issue affects Apache Shiro: from 1.*, 2.* before 2.0.7. Users are recommended to upgrade to version 2.0.7 or later, which fixes the issue. Prior to Shiro 2.0.7, code paths for non-existent vs. existing users are different enough, that a brute-force attack may be able to tell, by timing the requests only, determine if the request failed because of a non-existent user vs. wrong password. The most likely attack vector is a local attack only. Shiro security model https://shiro.apache.org/security-model.html#username_enumeration

O3 Security · Impact-Aware SCA

Is GHSA-c4qc-4q9p-m9q9 in your dependencies?

O3 Security finds GHSA-c4qc-4q9p-m9q9 across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

Scan my dependencies How O3 SCA works