CVE-2026-32144: OCSP designated-responder authorization bypass via missing signature verification
- Is it exploited?
Not on CISA's list. CISA has not added it to the Known Exploited Vulnerabilities catalog as of . If CISA adds it, this page shows it as known exploited.
- How likely is exploitation in the next 30 days?
- 0.2%
Down from 0.3% on .
EPSS score, percentile 9.8 of all scored records. A probability estimated by FIRST, not a report of exploitation.
- How severe?
- 7.6 High
CVSS v4.0 base score, given by the CNA
- What should I do?
CISA has set no required action, because the vulnerability is not in KEV.
- Which versions are affected?
Affected
- 1.16
- 11.2
- 27.0
Unaffected from 1.20.3; from 1.17.1.2; from 11.5.4; from 11.2.12.7; from 28.4.2; from 27.3.4.10
Source: CISA KEV 2026.10.29, as of ; FIRST EPSS, as of ; CVE List, as of . About the data.
What to do
Workaround (from the CVE record)
For SSL users: * Do not enable OCSP validation setting (current default is {stapling, no_staple}) * Use CRL-based revocation checking by setting the {crl_check, true} SSL option instead For applications using public_key:pkix_ocsp_validate/5 directly: * Pass {is_trusted_responder_fun, Fun} option with a function that validates trusted responder certificates * Restrict OCSP responder access to trusted endpoints via network controls (only applicable if you control the OCSP infrastructure)
Advisories and patches
This summary is based on the CVE record as of . Check the vendor's advisory before you act: affected versions and fixes can change.
Affected products and versions
As listed in the CVE record.
| Status | Versions |
|---|---|
| Affected | 1.16 |
| Unaffected | from 1.20.3 |
| Unaffected | from 1.17.1.2 |
Versions not listed are: unknown.
| Status | Versions |
|---|---|
| Affected | 11.2 |
| Unaffected | from 11.5.4 |
| Unaffected | from 11.2.12.7 |
Versions not listed are: unknown.
| Status | Versions |
|---|---|
| Affected | 27.0 |
| Unaffected | from 28.4.2 |
| Unaffected | from 27.3.4.10 |
| Affected | 601a012837ea |
| Unaffected | from ac7ff528be85 |
| Unaffected | from 49033a6d93a5 |
Versions not listed are: unknown.
Versions the record lists as unaffected: 1.20.3, 1.17.1.2, 11.5.4, 11.2.12.7, 28.4.2, 27.3.4.10, ac7ff528be857c5d35eb29c7f24106e3a16d4891, 49033a6d93a5be0ee0dce04e1fb8b4ae7de1e0c0.
Source: CVE List, as of . About the data.
About this vulnerability
Improper Certificate Validation vulnerability in Erlang OTP public_key (pubkey_ocsp module) allows OCSP designated-responder authorization bypass via missing signature verification. The OCSP response validation in public_key:pkix_ocsp_validate/5 does not verify that a CA-designated responder certificate was cryptographically signed by the issuing CA. Instead, it only checks that the responder ce…
Summary: CVE record, as of .
- CISA has not added CVE-2026-32144 to its Known Exploited Vulnerabilities (KEV) catalog, as of 29 Oct 2026.
- The CVE record was published on 7 Apr 2026.
- The CVE record carries a CVSS v4.0 base score of 7.6 (High), given by its CNA.
- FIRST's EPSS model puts the probability of exploitation in the next 30 days at 0.2% (percentile 9.8), as of 29 Oct 2026. EPSS is a statistical estimate, not a report of exploitation.
- CISA's SSVC assessment in the CVE record: exploitation none, automatable no, technical impact total.
- The credits in the CVE record name AISLE as finder.
Source: CISA KEV 2026.10.29, as of ; CVE List, as of ; FIRST EPSS, as of . About the data.
Description
OCSP designated-responder authorization bypass via missing signature verification
Improper Certificate Validation vulnerability in Erlang OTP public_key (pubkey_ocsp module) allows OCSP designated-responder authorization bypass via missing signature verification. The OCSP response validation in public_key:pkix_ocsp_validate/5 does not verify that a CA-designated responder certificate was cryptographically signed by the issuing CA. Instead, it only checks that the responder certificate's issuer name matches the CA's subject name and that the certificate has the OCSPSigning extended key usage. An attacker who can intercept or control OCSP responses can create a self-signed certificate with a matching issuer name and the OCSPSigning EKU, and use it to forge OCSP responses that mark revoked certificates as valid. This affects SSL/TLS clients using OCSP stapling, which may accept connections to servers with revoked certificates, potentially transmitting sensitive data to compromised servers. Applications using the public_key:pkix_ocsp_validate/5 API directly are also affected, with impact depending on usage context. This vulnerability is associated with program files lib/public_key/src/pubkey_ocsp.erl and program routines pubkey_ocsp:is_authorized_responder/3. This issue affects OTP from OTP 27.0 before OTP 28.4.2 and OTP 27.3.4.10, corresponding to public_key from 1.16 before 1.20.3 and 1.17.1.2, and ssl from 11.2 before 11.5.4 and 11.2.12.7.
Source: CVE List, as of . About the data.
Weakness
CWE-295, 1 CAPEC
- CWE-295: Improper Certificate Validation
Attack patterns (CAPEC)
- CAPEC-459: Creating a Rogue Certification Authority Certificate
CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record.
Timeline
| Date | Event |
|---|---|
| CVE record published | |
| CVE record last updated |
References
3
Known exploited Erlang vulnerabilities
- CVE-2025-32433: Erlang Erlang/OTP SSH Server Missing Authentication for Critical Function Vulnerability