CVE-2026-46384
CVE-2026-46384 is a CWE-190 vulnerability in github.com/iskorotkov/avro/v2. O3 Security confirms whether CVE-2026-46384 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
iskorotkov/avro: Integer Overflow in Avro Decoder
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-2026-46384.
EPSS Exploitation Probability
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
github.com/iskorotkov/avro/v2Real-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
iskorotkov/avro is a fast Go Avro codec. Prior to 2.33.0, several Avro decoder paths read attacker-controlled 64-bit values from the wire format and either narrowed them to platform-sized int before bounds-checking, or summed them with overflow-prone signed-int arithmetic. On 32-bit targets (GOARCH=386, arm, mips, wasm, etc.), the truncation paths can silently bypass byte-slice limits, select the wrong union branch, or hit the OCF negative-make panic via wrap. Three sub-issues are not 32-bit-specific: cumulative-size arithmetic overflow in arrayDecoder.Decode / mapDecoder.Decode / mapDecoderUnmarshaler.Decode (wraps at math.MaxInt64 on amd64 / arm64 and bypasses MaxSliceAllocSize / MaxMapAllocSize), math.MinInt negation in block-header handling, and make([]byte, size) with a negative size in OCF block reads — all three panic or bypass caps on any platform, giving an attacker a denial-of-service primitive there. This vulnerability is fixed in 2.33.0.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/iskorotkov/avro/v2 | all versions | 2.33.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/iskorotkov/avro/v2. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/iskorotkov/avro/v2 to 2.33.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-46384 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 pinpoints whether CVE-2026-46384 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-46384. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
This vulnerability affects multiple Avro decoder code paths in affected Go Avro libraries. Red Hat Product Security has assessed this issue as an Important severity vulnerability. A remote unauthenticated attacker may supply specially crafted Avro payloads containing malformed or excessively large integer values that…
Frequently Asked Questions
Is CVE-2026-46384 in your dependencies?
O3 detects CVE-2026-46384 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.