CVE-2026-22796Network attack vector

Application crash via unchecked PKCS7 attribute type

Published Jan 27, 2026 · Updated Jan 27, 2026

Type confusion in affected OpenSSL releases allows attackers to crash applications that verify malformed signed PKCS#7 data. PKCS7_digest_from_attributes() reads a message-digest attribute through the ASN1_TYPE union without confirming V_ASN1_OCTET_STRING, dereferencing invalid memory. Exploitation requires an application to accept and verify attacker-supplied signed PKCS#7 data; the resulting impact is limited to an application crash.

CVSS severity5.3
Medium
EPSS probability0.52%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Type confusion in affected OpenSSL releases allows attackers to crash applications that verify malformed signed PKCS#7 data. PKCS7_digest_from_attributes() reads a message-digest attribute through the ASN1_TYPE union without confirming V_ASN1_OCTET_STRING, dereferencing invalid memory. Exploitation requires an application to accept and verify attacker-supplied signed PKCS#7 data; the resulting impact is limited to an application crash.

The record

CVE
CVE-2026-22796
Published
Jan 27, 2026
Updated
Jan 27, 2026
Vendor
OpenSSL Project
Product
OpenSSL
Classifications
CWE-754, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 27, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 27, 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=1.0.2 <1.0.2zn
  2. Affected versionversion=1.1.1 <1.1.1ze
  3. Affected versionversion=3.0.0 <3.0.19
  4. Affected versionversion=3.3.0 <3.3.6
  5. Affected versionversion=3.4.0 <3.4.4
  6. Affected versionversion=3.5.0 <3.5.5
  7. Affected versionversion=3.6.0 <3.6.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

OpenSSL Project · OpenSSLversion=1.0.2 <1.0.2zn; version=1.1.1 <1.1.1ze; version=3.0.0 <3.0.19; version=3.3.0 <3.3.6; version=3.4.0 <3.4.4; version=3.5.0 <3.5.5; version=3.6.0 <3.6.1

Published CVSS scores

5.3CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-754Improper Check for Unusual or Exceptional Conditions
T1499.004Application or System Exploitation

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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