How severe is CVE-2023-28118?

CVE-2023-28118 has a CVSS score of 7.5/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2023-28118?

CVE-2023-28118 affects the following packages: com.charleskorn.kaml:kaml (Maven). Ecosystems affected: Maven.

How do I fix CVE-2023-28118?

Update com.charleskorn.kaml:kaml to 0.53.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-28118 is resolved across your whole dependency graph.

How do I detect CVE-2023-28118 in my Maven dependencies?

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

How do I mitigate CVE-2023-28118 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-2023-28118 actively exploited in the wild?

No public exploit code has been indexed for CVE-2023-28118 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-2023-28118?

CVE-2023-28118 has an EPSS (Exploit Prediction Scoring System) score of 1.0%, placing it in the 62th 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-2023-28118?

CVE-2023-28118 is classified as CWE-776 (CWE-776). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2023-28118 published, and has it been updated?

CVE-2023-28118 was published on March 20, 2023 and was last updated on October 28, 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-2023-28118 — kaml

HIGHFix: charleskorn/kaml@5f82a2d

CVE-2023-28118 is a high-severity (CVSS 7.5) CWE-776 vulnerability in com.charleskorn.kaml:kaml. A fix is available for com.charleskorn.kaml:kaml — see the affected versions and patch details below.

kaml has potential denial of service while parsing input with anchors and aliases

Also known asGHSA-c24f-2j3g-rg48

Published

Mar 20, 2023

Updated

Oct 28, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 30, 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.
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-2023-28118.

EPSS Exploitation Probability

via FIRST.org ↗

1.0%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs62th percentile — riskier than 62% of all scored CVEsHighest risk

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

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

1 pkg affected

☕com.charleskorn.kaml:kaml

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

Impact

Applications that use kaml to parse untrusted input containing anchors and aliases may consume excessive memory and crash.

Patches

Version 0.53.0 and later default to refusing to parse YAML documents containing anchors and aliases.

Workarounds

None.

References

Wikipedia has an explanation of this class of vulnerability: billion laughs attack

Acknowledgements

Thank you to @gdude2002 for reporting this issue.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`com.charleskorn.kaml:kaml`	all versions	0.53.0`com.charleskorn.kaml:kaml:0.53.0`

Affected Products

1 product · 1 configurations

Application

kamlkaml_project

< 0.53.0

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for com.charleskorn.kaml:kaml, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update com.charleskorn.kaml:kaml to 0.53.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-28118 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

### Impact Applications that use kaml to parse untrusted input containing anchors and aliases may consume excessive memory and crash. ### Patches Version 0.53.0 and later default to refusing to parse YAML documents containing anchors and aliases. ### Workarounds None. ### References Wikipedia has an explanation of this class of vulnerability: [billion laughs attack](https://en.wikipedia.org/wiki/Billion_laughs_attack) ### Acknowledgements Thank you to @gdude2002 for reporting this issue.