Live Exposure Defense: From CVE to Confirmed Exposure in 12 Hours – See more

Back
New CVE Detected

CVE-2026-54251 – Denial of Service (Native Memory Exhaustion) – Netty netty-incubator-codec-ohttp <

Be the first to know when new zero-days emerge:

Subscribe to Email Alerts
Subscribe to RSS Feed

Summary

CVE-2026-54251 is a native direct-memory leak vulnerability in netty-incubator-codec-ohttp, the Netty incubator module implementing Oblivious HTTP (OHTTP) gateway and client functionality. An attacker can repeatedly send malformed encrypted requests to an OHTTP gateway to exhaust off-heap (native) memory, resulting in a Denial of Service. The issue carries a CVSS score of 8.7 (High) and requires no authentication or user interaction, making it remotely exploitable over the network.

Technical details

  • Root cause: The OHTTP gateway allocates a pooled direct ByteBuf to hold decrypted plaintext before the AEAD authentication tag is verified. If the tag check fails, the decryption routine throws a CryptoException, but the previously allocated buffer is never released because the allocation is not protected by a try/finally block.
  • Trigger conditions: An attacker sends OHTTP requests containing invalid/tampered ciphertext (failing AEAD tag verification) to the gateway endpoint.
  • Attack vector: Network-based, no privileges or user interaction required (CWE-664: Improper Control of a Resource Through its Lifetime).
  • Impact: Each failed decryption leaks a native direct-memory buffer. Repeated invalid requests progressively exhaust the JVM’s off-heap memory pool, ultimately crashing or hanging the OHTTP gateway process — a pure availability impact with no confidentiality or integrity loss.

Affected software

  • io.netty.incubator:netty-incubator-codec-ohttp (Maven artifact): versions before 0.0.23.Final
  • netty-incubator-codec-ohttp (all distributions of the incubator OHTTP codec): versions before 0.0.23.Final

Severity

  • CVSS v4.0 Base Score: 8.7 (High)
  • Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Mitigation and recommended actions

  • Immediate: Upgrade netty-incubator-codec-ohttp to version 0.0.23.Final or later, which fixes the buffer release logic by properly guarding the decrypted-buffer allocation with exception-safe (try/finally) release handling.
  • If immediate patching is not possible:
    • Monitor native/direct memory usage on hosts running OHTTP gateways for abnormal growth trends.
    • Apply rate limiting or request throttling on OHTTP gateway endpoints to limit the volume of malformed requests any single client can submit.
    • Consider deploying application-level restarts/health checks that detect and recover from native memory exhaustion until the patched version can be rolled out.

References

Are you exposed?

Get a free report of your organization’s exposure to this CVE and threat

  • Mapping of all Assets with this Technology
  • Identification of potentially exposed assets to this CVE
  • Confirmation of verified exploitable assets
Get Exposure Report

How IONIX’s External Exposure Management Platform Detects and Validates
Zero-Days to Shrink MTTR

1

Map your entire attack surface (continously)

IONIX uses multi-factor discovery methods, including DNS analysis, certificate mapping, metadata inspection, and more, to automatically map every internet-facing asset across your environment. This includes cloud instances, third-party platforms, shadow IT, and even forgotten infrastructure that traditional tools miss.

2

Monitor for new CVEs

Dozens of threat intel feeds using agentic technology are continuously analyzed to detect the appearance of proof-of-concept code, exploit kits, and indicators of active targeting. IONIX goes further by applying AI to proactively evaluate whether emerging vulnerabilities are likely to be exploited, even before PoCs go public.

3

Identify Potential External Exposures

Not all CVEs matter. IONIX filters vulnerabilities by asking attacker-centric questions: Can it be reached from the internet? Does it require authentication? Is it being exploited in the wild? This dramatically reduces noise and focuses teams on threats that can actually be weaponized.

4

Create Safe, Scalable Exploit Validations

IONIX transforms real-world PoCs into safe, non-intrusive test payloads that can be run in production environments without disruption. These simulations are precisely targeted to the systems that are vulnerable, ensuring rapid validation without unnecessary load.

5

Execute Exploit Validations

By combining context about software stack, versioning, exposure status, and reachability, IONIX ensures that only the right payloads are executed against the right assets, maximizing efficiency and minimizing risk.

6

Drive Fast and Actionable Remediation

Results are routed through integrations with ticketing, SOAR, and SIEM tools. Issues are written in plain language, bundled into remediation clusters, and prioritized based on asset criticality, exploitability, and blast radius. This shortens mean time to remediation (MTTR) and empowers teams to act with confidence.

Are you exposed?

Get a free report of your organization’s exposure to this CVE and threat

  • Mapping of all Assets with this Technology
  • Identification of potentially exposed assets to this CVE
  • Confirmation of verified exploitable assets
Get Exposure Report
Close

Subscribe to Threat Center RSS

Copy/paste the link below into your preferred RSS reader or follow these instructions to subscribe to Slack alerts.

Open RSS feedSlack setup instructions

Close

Get Real-Time CVE Alerts to Your Email

Be the first to know when new zero-days emerge