How severe is CVE-2021-29262?

CVE-2021-29262 has a CVSS score of 7.5/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2021-29262?

CVE-2021-29262 affects the following packages: org.apache.solr:solr-core (Maven). Ecosystems affected: Maven.

How do I fix CVE-2021-29262?

Update org.apache.solr:solr-core to 8.8.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-29262 is resolved across your whole dependency graph.

How do I detect CVE-2021-29262 in my Maven dependencies?

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

How do I mitigate CVE-2021-29262 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.

Is CVE-2021-29262 actively exploited in the wild?

No public exploit code has been indexed for CVE-2021-29262 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-2021-29262?

CVE-2021-29262 has an EPSS (Exploit Prediction Scoring System) score of 6.7%, placing it in the 94th 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-2021-29262?

CVE-2021-29262 is classified as CWE-522 (CWE-522). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2021-29262 published, and has it been updated?

CVE-2021-29262 was published on April 13, 2021 and was last updated on October 24, 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

HIGH severity

CVE-2021-29262 — solr-core

HIGH

CVE-2021-29262 is a high-severity (CVSS 7.5) CWE-522 vulnerability in org.apache.solr:solr-core. A fix is available for org.apache.solr:solr-core — see the affected versions and patch details below.

Improper permission handling in Apache Solr

Also known asBIT-solr-2021-29262GHSA-jgcr-fg3g-qvw8

Published

Apr 13, 2021

Updated

Oct 24, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 25, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

6.7%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs94th percentile — riskier than 94% of all scored CVEsHighest risk

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

How urgent is this, really

CVE-2021-29262 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 395,492 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

☕org.apache.solr:solr-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

When starting Apache Solr versions prior to 8.8.2, configured with the SaslZkACLProvider or VMParamsAllAndReadonlyDigestZkACLProvider and no existing security.json znode, if the optional read-only user is configured then Solr would not treat that node as a sensitive path and would allow it to be readable. Additionally, with any ZkACLProvider, if the security.json is already present, Solr will not automatically update the ACLs.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`org.apache.solr:solr-core`	all versions	8.8.2`org.apache.solr:solr-core:8.8.2`

Affected Products

1 product · 1 configurations

Application

solrapache

< 8.8.2

range

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.solr:solr-core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.apache.solr:solr-core to 8.8.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-29262 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.

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is CVE-2021-29262 in your dependencies?

Find it across Maven, including transitive dependencies.

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