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Out-of-bounds WriteWeakness · CWE-787

CVE-2026-5190

HIGH · 7.5 CVSS v3.1 Published 2026-03-31
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
82/100
Remediation priority · High
Remotely reachable No privileges

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Out-of-bounds write in the streaming decoder component in aws-c-event-stream before 0.6.0 might allow a third party operating a server to cause memory corruption leading to arbitrary code execution on a client application that processes crafted event-stream messages. To remediate this issue, users should upgrade to version 0.6.0 or later.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

This is an out-of-bounds write vulnerability in the streaming decoder of the aws-c-event-stream library versions prior to 0.6.0. A malicious third-party server can send crafted event-stream messages that trigger memory corruption in the client application, potentially leading to arbitrary code execution.

MitigationUpgrade aws-c-event-stream to version 0.6.0 or later. Since this is a library dependency, identify all applications using this library and update the dependency version, then conduct regression testing to ensure compatibility.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
High
Privileges
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify aws-c-event-stream library presence
    Search for aws-c-event-stream in installed packages, linked libraries, or dependency manifests (package.json, Cargo.toml, requirements.txt, or build system outputs like CMake or Make). Also check for static/dynamic library files (libaws-c-event-stream.a or .so) in system or project directories.
    Affected if The library is present in the environment or project dependencies.
  2. Determine installed library version
    Run version lookup commands appropriate to the package manager or build system (for example: npm list aws-c-event-stream, pip show aws-c-event-stream, or check library symbols if compiled). Look for version information in header files, build metadata, or library file metadata.
    Affected if The version returned is lower than 0.6.0.
  3. Verify streaming decoder component usage
    Inspect code or configuration for usage of event-stream decoding functions from aws-c-event-stream (typically functions named something like aws_event_stream_decoder_*, aws_event_stream_read_message, or similar streaming API calls). Check if the application processes incoming event-stream data from network sources.
    Affected if The streaming decoder functions are called to process incoming event-stream data.
  4. Confirm network exposure to untrusted event-stream servers
    Review application architecture to determine if it acts as a client connecting to remote servers that send event-stream messages, or accepts event-stream input from external sources.
    Affected if The application receives event-stream messages from network sources that could be controlled by an attacker.

If aws-c-event-stream library version is below 0.6.0 and the streaming decoder processes incoming event-stream data from network sources, the environment is vulnerable to memory corruption via out-of-bounds write.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade aws-c-event-stream to version 0.6.0 or later. Since this is a library dependency, identify all applications using this library and update the dependency version, then conduct regression testing to ensure compatibility.

Recommended fix High confidence

aws-c-event-stream version 0.6.0

  1. Identify the current version of aws-c-event-stream in use by checking project dependencies (e.g., package.json, Cargo.toml, requirements.txt, or package manager lock files)
  2. Update the aws-c-event-stream dependency to version 0.6.0 or later in your project's dependency manifest
  3. Run dependency update commands appropriate to your package manager (e.g., npm update, cargo update, pip install -U, or similar)
  4. Rebuild the application to incorporate the updated library
  5. Verify the upgrade was successful by checking the installed version matches 0.6.0 or later
  6. Run existing tests to ensure functionality is not broken

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation4.0 h
  • Implementation2.0 h
  • Testing8.0 h
  • Review / QA4.0 h
18.0 hours of engineering $3,080
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-5190 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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