CVE-2026-44378Network attack vector

CPU exhaustion via indefinite-length BER parsing

Published May 27, 2026 · Updated May 27, 2026

Algorithmic complexity in Randombit Botan before 3.12.0 allows remote attackers to exhaust CPU via crafted ASN.1 data. BER_Decoder accepts indefinite-length BER in X.509, OCSP, and other PKIX structures that require canonical DER, causing quadratic parsing work. Unauthenticated access to any ASN.1 input path, including certificate or OCSP-response handling, can consume CPU and interrupt the embedding service.

CVSS severity7.5
High
EPSS probability0.32%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Algorithmic complexity in Randombit Botan before 3.12.0 allows remote attackers to exhaust CPU via crafted ASN.1 data. BER_Decoder accepts indefinite-length BER in X.509, OCSP, and other PKIX structures that require canonical DER, causing quadratic parsing work. Unauthenticated access to any ASN.1 input path, including certificate or OCSP-response handling, can consume CPU and interrupt the embedding service.

The record

CVE
CVE-2026-44378
Published
May 27, 2026
Updated
May 27, 2026
Vendor
Botan Project
Product
Botan
Classifications
CWE-407, T1499.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 27, 2026CVE publishedPublication date reported by the CVE source.
  2. May 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=< 3.12.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Botan Project · Botanversion=< 3.12.0

Published CVSS scores

7.5NIST National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
6.9GitHub, Inc.CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

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-407Inefficient Algorithmic Complexity
T1499.002Service Exhaustion

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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