CVE-2025-32033 is a high-severity (CVSS 7.5) Buffer Overflow vulnerability in apollo-router. A fix is available for apollo-router — see the affected versions and patch details below.
Apollo Router Operation Limits Vulnerable to Bypass via Integer Overflow
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-2025-32033.
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
apollo-router🦀apollo-routerReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.
Description
Impact
Summary
A vulnerability in Apollo Router allowed certain queries to bypass configured operation limits, specifically due to integer overflow.
Details
The operation limits plugin uses unsigned 32-bit integers to track limit counters (e.g. for a query's height). If a counter exceeded the maximum value for this data type (4,294,967,295), it wrapped around to 0, unintentionally allowing queries to bypass configured thresholds. This could occur for large queries if the payload limit were sufficiently increased, but could also occur for small queries with deeply nested and reused named fragments.
Fix/Mitigation
Logic was updated to ensure counter overflow is handled correctly and does not wrap around to 0.
Patches
This has been remediated in apollo-router versions 1.61.2 and 2.1.1.
Workarounds
The only known workaround is "Safelisting" or "Safelisting with IDs only" per Safelisting with Persisted Queries - Apollo GraphQL Docs.
Acknowledgements
We appreciate the efforts of the security community in identifying and improving the performance and security of operation limiting mechanisms.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | apollo-router | all versions | 1.61.2cargo update -p apollo-router --precise 1.61.2 |
| 🦀crates.io | apollo-router | ≥ 2.0.0-alpha.0&&< 2.1.1 | 2.1.1cargo update -p apollo-router --precise 2.1.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for apollo-router, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update apollo-router to 1.61.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-32033 is resolved across your whole dependency graph.
Workarounds
Constrain what reaches the vulnerable code: limit the size and shape of untrusted input, isolate the affected component in a sandboxed or least-privileged process, and enable the platform's memory-safety mitigations (ASLR, stack protector, hardened allocator) so an out-of-bounds access is more likely to fail closed than to be exploitable.
Frequently Asked Questions
Is CVE-2025-32033 in your dependencies?
Find it across crates.io, including transitive dependencies.