CVE-2023-28119 is a high-severity (CVSS 7.5) CWE-770 vulnerability in github.com/crewjam/saml. A fix is available for github.com/crewjam/saml — see the affected versions and patch details below.
crewjam/saml vulnerable to Denial Of Service Via Deflate Decompression Bomb
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-2023-28119.
EPSS Exploitation Probability
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
github.com/crewjam/samlReal-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
The crewjam/saml go library contains a partial implementation of the SAML standard in golang. Prior to version 0.4.13, the package's use of flate.NewReader does not limit the size of the input. The user can pass more than 1 MB of data in the HTTP request to the processing functions, which will be decompressed server-side using the Deflate algorithm. Therefore, after repeating the same request multiple times, it is possible to achieve a reliable crash since the operating system kills the process. This issue is patched in version 0.4.13.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/crewjam/saml | all versions | 0.4.13go get github.com/crewjam/saml@v0.4.13 |
Affected Products
samlsaml_projectDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/crewjam/saml, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/crewjam/saml to 0.4.13 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-28119 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.
Frequently Asked Questions
Is CVE-2023-28119 in your dependencies?
Find it across Go, including transitive dependencies.