CVE-2026-48040 — netty-incubator-codec-oht…
Fix: netty/netty-incubator-codec-ohttp@7ad38d5CVE-2026-48040 is a Out-of-bounds Read vulnerability in io.netty.incubator:netty-incubator-codec-ohttp-hpke-native-boringssl. A fix is available for io.netty.incubator:netty-incubator-codec-ohttp-hpke-native-boringssl — see the affected versions and patch details below.
netty-incubator-codec-ohttp's Incorrect Native Pointer Derivation in Pooled Direct ByteBuf Fallback Leads to Out-of-Bounds Native Memory Access
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.
- A successful exploit gives an attacker total control of the affected component, not partial access.
- 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-2026-48040.
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
io.netty.incubator:netty-incubator-codec-ohttp-hpke-native-boringsslReal-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
The netty incubator codec.bhttp is a java language binary http parser. The library implements Oblivious HTTP (RFC 9458) using BoringSSL's HPKE C library via JNI. When deriving native memory addresses for cryptographic operations versions prior to 0.0.22.Final provide a fallback path for direct ByteBufs that do not expose their memory address through hasMemoryAddress(). This fallback occurs when sun.misc.Unsafe is unavailable to Netty — for example, when the JVM is started with -Dio.netty.noUnsafe=true, when a SecurityManager restricts Unsafe access, or when running on non-HotSpot JVMs. In these configurations, Netty's default PooledByteBufAllocator returns PooledDirectByteBuf instances for which hasMemoryAddress() returns false. Under the enabling JVM configuration, an unauthenticated network attacker can cause the OHTTP gateway to corrupt memory belonging to other concurrent connections and disclose the contents of adjacent pooled direct buffers by triggering cryptographic operations with crafted OHTTP requests. The corruption occurs regardless of whether the AEAD tag verification succeeds, as BoringSSL zeroizes the output buffer on failure. The information disclosure path provides the attacker with the encryption key needed to extract the leaked data. This violates the confidentiality and integrity of all connections sharing the same Netty buffer arena. Version 0.0.22.Final fixes the issue.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | io.netty.incubator:netty-incubator-codec-ohttp-hpke-native-boringssl | all versions | 0.0.22.Finalio.netty.incubator:netty-incubator-codec-ohttp-hpke-native-boringssl:0.0.22.Final |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for io.netty.incubator:netty-incubator-codec-ohttp-hpke-native-boringssl, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update io.netty.incubator:netty-incubator-codec-ohttp-hpke-native-boringssl to 0.0.22.Final or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-48040 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-48040 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-48040. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-48040 in your dependencies?
O3 Security finds CVE-2026-48040 across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.