OTP: Improper Certificate Validation
CVE-2026-32144 is a high-severity improper certificate validation vulnerability in OTP from Erlang, with a CVSS 3.1 base score of 7.4 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected OTP versions: 27.0 and later; 1.16 and later; 11.2 and later, and others listed below. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.21% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Erlang/otp to 27.3.4.10 or 28.4.2, whichever matches your release line, or a later version.
- Update Erlang/public Key to 1.17.1.2 or 1.20.3, whichever matches your release line, or a later version.
- Update Erlang/ssl to 11.2.12.7 or 11.5.4, whichever matches your release line, or a later version.
- Read the advisory on cna.erlef.org for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Erlang | OTP | 27.0 and later; 1.16 and later; 11.2 and later; 601a012837ea0a5c8095bf24223132824177124d and later | Not stated |
| Red Hat | Red Hat OpenStack Platform 16.2 | Not specified in the record | Not stated |
| Red Hat | Red Hat OpenStack Platform 17.1 | Not specified in the record | Not stated |
| Red Hat | Red Hat OpenStack Platform 18.0 | Not specified in the record | Not stated |
| Erlang | Erlang/otp | 27.0 up to, but not including, 27.3.4.10; 28.0 up to, but not including, 28.4.2 | 27.3.4.10, 28.4.2 |
| Erlang | Erlang/public Key | 1.16 up to, but not including, 1.17.1.2; 1.18 up to, but not including, 1.20.3 | 1.17.1.2, 1.20.3 |
| Erlang | Erlang/ssl | 11.2 up to, but not including, 11.2.12.7; after 11.3 up to, but not including, 11.5.4 | 11.2.12.7, 11.5.4 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- HighSuccess depends on conditions outside the attacker's control.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 7.6 | High | CNA |
| CVSS 3.1 | 7.4 | High | NVD |
| CVSS 3.1 | 7.4 | High | CNA |
Official description
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 27.3.4.10 and OTP 28.4.2, corresponding to public_key from 1.16 before 1.17.1.2 and 1.20.3, and ssl from 11.2 before 11.2.12.7 and 11.5.4.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Certificate Validation
The product does not validate, or incorrectly validates, a certificate.
How developers prevent this class of flaw
- Certificates should be carefully managed and checked to assure that data are encrypted with the intended owner's public key.
- If certificate pinning is being used, ensure that all relevant properties of the certificate are fully validated before the certificate is pinned, including the hostname.
More Improper Certificate Validation vulnerabilities (CWE-295)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
- cna.erlef.org/cves/CVE-2026-32144.htmlMitigation
- github.com/erlang/otp/security/advisories/GHSA-gxrm-pf64-99xmMitigation, Third Party Advisory
- erlang.org/doc/system/versions.html#order-of-versions
Patches and release notes
Third-party and government advisories
- osv.dev/vulnerability/EEF-CVE-2026-32144Third Party Advisory
Other references
Other vulnerabilities in OTP
- 8.2 High severity
- 9.3 Critical severity
- 7.1 High severity
- 8.2 High severity
- 8.2 High severity
- 8.7 High severity
Recent Improper Certificate Validation vulnerabilities
- 7.5 High severity
- 8.2 High severity
- 7.5 High severity
- 10.0 Critical severity
- 9.1 Critical severity
- 8.1 High severity
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