BotanApplication · Botan Project

CVE-2026-44378

HIGH · 7.5 CVSS v3.1 Published 2026-05-27
Fix available
A fix is available. Upgrade to 3.12.0 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Botan is a C++ cryptography library. Prior to 3.12.0, certain patterns of indefinite length encodings in BER data could cause quadratic behavior in the parser, resulting in a denial of service. Such BER encodings were accepted even in structures which are required to be encoded as DER, which prohibits indefinite length encodings. This vulnerability is fixed in 3.12.0.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

A denial of service vulnerability in Botan versions prior to 3.12.0 allows attackers to trigger quadratic parsing behavior by sending specially crafted BER data with indefinite length encodings. The parser incorrectly accepts BER indefinite length encodings even in contexts where DER is required (which prohibits such encodings), causing excessive CPU consumption and service unavailability.

MitigationUpgrade Botan to version 3.12.0 or later to remediate this vulnerability. If immediate upgrade is not feasible, consider restricting or validating input data to reject BER-encoded content in DER-required contexts as a temporary mitigation.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
BotanApplication
Affected:< 3.12.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify Botan library version
    Locate the installed Botan library (libbotan.so, botan.dll, or Python bindings) and query its version using 'botan --version', 'python3 -c "import botan; print(botan.version)"', or by checking the file metadata of the library binary
    Affected if The installed version is any version prior to 3.12.0 (e.g., 3.11.0, 3.10.0, 2.x, etc.)
  2. Identify applications using Botan
    Search for processes or applications that link against the Botan library using 'ldd <binary>' on Linux or by reviewing application dependencies. Check for any services that parse X.509 certificates, TLS handshakes, or other ASN.1/BER-encoded data
    Affected if Any application using Botan to parse BER or DER encoded data (especially X.509 certificates, CRLs, OCSP responses, or TLS handshake messages)
  3. Inspect input handling for BER content
    Review application logs, network capture, or configuration to determine if the service accepts or processes BER-encoded input, particularly in contexts where strict DER is required. Look for: (1) loading external X.509 certificates, (2) processing PKCS#10 CSR, (3) validating signed data from untrusted sources
    Affected if The application accepts BER-encoded content from untrusted sources, especially certificates, CSRs, or signed objects that should be DER-constrained
  4. Monitor for quadratic parsing behavior
    If the service is currently running, monitor CPU usage during BER data processing. The vulnerability causes repeated re-scanning of the input buffer during length parsing, leading to CPU spikes. Use 'top', 'htop', or process monitoring to observe CPU consumption during certificate/ASN.1 parsing operations
    Affected if CPU consumption becomes excessive when processing certain BER inputs with indefinite length encodings, or parsing takes significantly longer than expected for small inputs

You are affected if your installed Botan version is prior to 3.12.0 AND your application processes BER-encoded ASN.1 data (especially certificates, CSRs, or signed objects) from untrusted sources.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 3.12.0 or later
Fixed in 3.12.0
Interim mitigation

Upgrade Botan to version 3.12.0 or later to remediate this vulnerability. If immediate upgrade is not feasible, consider restricting or validating input data to reject BER-encoded content in DER-required contexts as a temporary mitigation.

Recommended fix High confidence

Botan 3.12.0

  1. 1. Identify the current version of Botan in use by examining project dependencies or running version check command
  2. 2. Obtain Botan 3.12.0 from the official source (github.com/botan/botan/releases or package manager)
  3. 3. Replace the existing Botan library files with the new version 3.12.0
  4. 4. Rebuild and recompile any projects that link against the Botan library
  5. 5. Verify the upgrade by running application tests to ensure functionality is intact
  6. 6. Confirm the installed version is 3.12.0 or higher
Caveat Review Botan 3.12.0 release notes for any API changes or breaking changes before upgrading

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Botan Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing8.0 h
  • Review / QA4.0 h
24.0 hours of engineering $4,160
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-44378 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data