CVE-2026-63076Network attack vector

Service crash via mistyped CMP protection parameter

Published Aug 25, 2026 · Updated Aug 25, 2026

Invalid pointer dereference in OpenSSL CMP PBM verification allows remote attackers to crash CMP clients or servers with a crafted message. X509_ALGOR_get0() returns a parameter type and value, but verification ignores the type and casts any non-NULL value to ASN1_STRING as a PBMParameter. The unauthenticated server path requires an application with CMP PBM verification enabled; clients are exposed to malicious or intercepted CMP servers, and the bounded consequence is a process crash.

CVSS severity7.5
High
EPSS probability1.35%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Invalid pointer dereference in OpenSSL CMP PBM verification allows remote attackers to crash CMP clients or servers with a crafted message. X509_ALGOR_get0() returns a parameter type and value, but verification ignores the type and casts any non-NULL value to ASN1_STRING as a PBMParameter. The unauthenticated server path requires an application with CMP PBM verification enabled; clients are exposed to malicious or intercepted CMP servers, and the bounded consequence is a process crash.

The record

CVE
CVE-2026-63076
Published
Aug 25, 2026
Updated
Aug 25, 2026
Vendor
OpenSSL Project
Product
OpenSSL
Classifications
CWE-476, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 25, 2026Record 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=3.0.0 <3.0.22
  2. Affected versionversion=3.4.0 <3.4.7
  3. Affected versionversion=3.5.0 <3.5.8
  4. Affected versionversion=3.6.0 <3.6.4
  5. Affected versionversion=4.0.0 <4.0.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

OpenSSL Project · OpenSSLversion=3.0.0 <3.0.22; version=3.4.0 <3.4.7; version=3.5.0 <3.5.8; version=3.6.0 <3.6.4; version=4.0.0 <4.0.2

Published CVSS scores

7.5CISACVSS: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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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-476NULL Pointer Dereference
T1499.004Application or System Exploitation DoS

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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