CVE-2026-32883 | Botan: Missing OCSP Response Signature Verification Allows MitM Certificate Revocation Bypass

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.

Published: 2026-03-30 Last update: 2026-04-13 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-32883 is rated Low Risk (25.4/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.02%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-32883

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-03-31 — 0.02% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-32883

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.9 3.1 MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 2.2 3.6 [email protected]

Weakness enumeration for CVE-2026-32883

OS Trackers for CVE-2026-32883

vendor priority summary link
debian unimportant CVE-2026-32883 unimportant priority: Debian including 2 source packages (botan, botan3), 6 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5, open 1. https://security-tracker.debian.org/tracker/CVE-2026-32883
redhat medium — https://access.redhat.com/security/cve/CVE-2026-32883
ubuntu medium CVE-2026-32883 medium priority: Ubuntu including 3 source packages (botan, botan1.10, botan3), 17 status rows across 8 suites (bionic, focal, jammy, noble, questing, trusty, upstream, xenial): needs-triage 12, DNE 5. https://ubuntu.com/security/CVE-2026-32883

Affected software / configurations for CVE-2026-32883

Vendor Product Version Raw CPE
botan_project botan >= 3.0.0, < 3.11.0 cpe:2.3:a:botan_project:botan:*:*:*:*:*:*:*:*

References for CVE-2026-32883

cvelogic Threat Intelligence