CVE-2026-32883

Botan: Missing OCSP Response Signature Verification Allows MitM Certificate Revocation Bypass

MEDIUM
5.9
CVSS Score
Published: March 30, 2026 at 08:36 PM UTC
Updated: June 17, 2026 at 10:36 AM UTC
2 products affected across 2 vendorsBotanBotan

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Severity
MEDIUM5.9
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

Description

Botan is a C++ cryptography library. From version 3.0.0 to before version 3.11.0, during X509 path validation, OCSP responses were checked for an appropriate status code, but critically omitted verifying the signature of the OCSP response itself. This issue has been patched in version 3.11.0.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

3.0.0 ≤ v < 3.11.0
v < 3.11.0
Affected range stops below 3.11.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (1)

x_refsource_CONFIRMVendor Advisory
Source: cverecord
https://github.com/randombit/botan/security/advisories/GHSA-9j2j-hqmc-hf5x

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5.9MEDIUMGitHub_M
Attack Vector
NETWORK
Complexity
HIGH
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
HIGH
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-347

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