CVE-2026-8507Network attack vector

Code execution via signed attribute-length overflow

Published May 17, 2026 · Updated May 17, 2026

An out-of-bounds write in Crypt::OpenSSL::PKCS12 1.94 and earlier allows remote attackers to execute code via a crafted PKCS12 file. In PKCS12.xs, print_attribute multiplies an attacker-controlled OCTET STRING or BIT STRING length by four as a signed int, so Renew allocates a near-empty heap buffer before get_hex writes roughly 3 GiB past it. Exploitation requires an application to parse an untrusted bundle and call info() or info_as_hash(); resulting code runs with that process's privileges.

CVSS severity9.8
Critical
EPSS probability0.65%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

An out-of-bounds write in Crypt::OpenSSL::PKCS12 1.94 and earlier allows remote attackers to execute code via a crafted PKCS12 file. In PKCS12.xs, print_attribute multiplies an attacker-controlled OCTET STRING or BIT STRING length by four as a signed int, so Renew allocates a near-empty heap buffer before get_hex writes roughly 3 GiB past it. Exploitation requires an application to parse an untrusted bundle and call info() or info_as_hash(); resulting code runs with that process's privileges.

The record

CVE
CVE-2026-8507
Published
May 17, 2026
Updated
May 17, 2026
Vendor
Jonas B. Nielsen
Product
Crypt::OpenSSL::PKCS12
Classifications
CWE-787
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 17, 2026CVE publishedPublication date reported by the CVE source.
  2. May 17, 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?

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  1. Affected versionversion=0 <=1.94

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Jonas B. Nielsen · Crypt::OpenSSL::PKCS12version=0 <=1.94

Published CVSS scores

9.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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-787Out-of-bounds Write

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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