CVE-2026-28390Network attack vector

Application crash via missing RSA-OAEP parameters

Published Apr 7, 2026 · Updated Apr 7, 2026

NULL pointer dereference in OpenSSL affected branches allows remote attackers to crash applications via crafted CMS EnvelopedData. The rsa_cms_decrypt function reads the optional RSA-OAEP SourceFunc parameter without first confirming that the ASN.1 field is present. Reachability requires an application or service to call CMS_decrypt on attacker-controlled CMS data; affected processes crash before authentication or cryptographic operations, while OpenSSL FIPS modules remain outside the affected code path.

CVSS severity7.5
High
EPSS probability0.80%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in OpenSSL affected branches allows remote attackers to crash applications via crafted CMS EnvelopedData. The rsa_cms_decrypt function reads the optional RSA-OAEP SourceFunc parameter without first confirming that the ASN.1 field is present. Reachability requires an application or service to call CMS_decrypt on attacker-controlled CMS data; affected processes crash before authentication or cryptographic operations, while OpenSSL FIPS modules remain outside the affected code path.

The record

CVE
CVE-2026-28390
Published
Apr 7, 2026
Updated
Apr 7, 2026
Vendor
OpenSSL Project
Product
OpenSSL
Classifications
CWE-476, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 7, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 7, 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 <1.0.2zp
  2. Affected versionversion=1.1.1 <1.1.1zg
  3. Affected versionversion=3.0.0 <3.0.20
  4. Affected versionversion=3.3.0 <3.3.7
  5. Affected versionversion=3.4.0 <3.4.5
  6. Affected versionversion=3.5.0 <3.5.6
  7. Affected versionversion=3.6.0 <3.6.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

OpenSSL Project · OpenSSLversion=1.0.2 <1.0.2zp; version=1.1.1 <1.1.1zg; version=3.0.0 <3.0.20; version=3.3.0 <3.3.7; version=3.4.0 <3.4.5; version=3.5.0 <3.5.6; version=3.6.0 <3.6.2

Published CVSS scores

7.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
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.

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
T1499Endpoint Denial of Service

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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