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CVE-2026-48040

Netty Netty-incubator-codec-ohttp buffer overflow

9.1 CRITICALEPSS 0.29%
  1. Published4 Jun 2026

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.

CVSS 3.1 breakdown

Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionNone
ScopeUnchanged
ConfidentialityHigh
IntegrityHigh
AvailabilityNone
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Affected products

Netty Netty-incubator-codec-ohttp< 0.0.22

Frequently asked

Is CVE-2026-48040 being actively exploited?

CVE-2026-48040 is not in the CISA KEV catalog. Its EPSS exploit probability is 0.29%.

How severe is CVE-2026-48040?

CVE-2026-48040 has a CVSS 3.1 base score of 9.1, rated critical. EPSS estimates a 0.29% probability of exploitation.

Which products are affected by CVE-2026-48040?

Affected products include Netty Netty-incubator-codec-ohttp.

How do I fix CVE-2026-48040?

Upgrade affected software to a fixed version, for example Netty Netty-incubator-codec-ohttp 0.0.22 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2026-48040 against the real software inventory on every managed device, every day. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.