CVE-2026-48040 netty-incubator-codec-ohttp's Incorrect Native Pointer Derivation in Pooled Direct ByteBuf Fallback Leads to Out-of-Bounds Native Memory Access
An attacker can corrupt memory and disclose encryption keys in Netty OHTTP codec when Unsafe is disabled, compromising connection confidentiality and integrity.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-48040?
CVE-2026-48040 is a medium-severity memory corruption vulnerability in netty-incubator-codec-ohttp, published on 4 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Which versions are affected by CVE-2026-48040?
2 open source packages ship an affected version, including io.netty.incubator:netty-incubator-codec-ohttp-hpke-native-boringssl. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
io.netty.incubator:netty-incubator-codec-ohttp-hpke-native-boringssl Maven | All versions | 0.0.22.Final |
io.netty.incubator:netty-incubator-codec-ohttp-hpke-native-boringssl Maven | All versions | 0.0.22.Final |
Products include Netty Netty-Incubator-Codec-Ohttp.
How do I fix CVE-2026-48040?
Upgrade io.netty.incubator:netty-incubator-codec-ohttp-hpke-native-boringssl to 0.0.22.Final or later.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-48040 being exploited?
There is no known exploitation of CVE-2026-48040 in the wild and no public exploit code.
Other vulnerabilities in netty-incubator-codec-ohttp
Sources
Also known as GHSA-32hf-8jw3-v4qq.