CVE-2023-1428Network attack vector

Server crash via invalid HTTP/2 metadata

Published Jun 9, 2023 · Updated Sep 26, 2024

Reachable assertion in gRPC C++ 1.51.0 through versions before 1.53.0 allows remote attackers to crash servers via crafted HTTP/2 headers. The HPACK parser calls each metadata key's Encode method while computing header-size summaries; invalid te, :scheme, or grpclb_client_stats values make that operation abort instead of returning a parse error. Any unauthenticated network client that can reach an affected gRPC C++ server can cross the 8 KB metadata limit and terminate its process, interrupting service.

CVSS severity7.5
High
EPSS probability0.41%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reachable assertion in gRPC C++ 1.51.0 through versions before 1.53.0 allows remote attackers to crash servers via crafted HTTP/2 headers. The HPACK parser calls each metadata key's Encode method while computing header-size summaries; invalid te, :scheme, or grpclb_client_stats values make that operation abort instead of returning a parse error. Any unauthenticated network client that can reach an affected gRPC C++ server can cross the 8 KB metadata limit and terminate its process, interrupting service.

The record

CVE
CVE-2023-1428
Published
Jun 9, 2023
Updated
Sep 26, 2024
Vendor
gRPC
Product
gRPC
Classifications
CWE-617, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 9, 2023CVE publishedPublication date reported by the CVE source.
  2. Sep 26, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1.51.0 <1.53.0
  2. Affected versionversion=1.51 <1.53

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

gRPC · gRPCversion=1.51.0 <1.53.0; version=1.51 <1.53

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-617Reachable Assertion
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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