Cyber Resilience

CVE-2026-32144

Crypto Weakness in Erlang\/Otp 27.0 – 27.3.4.10

Published
07 April 2026
Modified
24 July 2026
Patch / advisory
CVSS Score v4 7.6
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0020 10th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-32144 is a high-severity Improper Certificate Validation (CWE-295) vulnerability in Erlang Erlang\/Otp. Its CVSS base score is 7.6 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Supply Chain Compromise (T1195); ranked at the 10th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SC-13 (Cryptographic Protection) and SC-17 (Public Key Infrastructure Certificates) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2026-32144 is an Improper Certificate Validation vulnerability in the Erlang/OTP public_key module's pubkey_ocsp component, specifically affecting the public_key:pkix_ocsp_validate/5 function and the pubkey_ocsp:is_authorized_responder/3 routine in lib/public_key/src/pubkey_ocsp.erl. The flaw enables an OCSP designated-responder authorization bypass because the validation does not cryptographically verify that the responder certificate is signed by the issuing CA; it only checks for a matching issuer name and the presence of the OCSPSigning extended key usage. This impacts Erlang/OTP (OTP) versions from 27.0 up to but excluding 28.4.2 and 27.3.4.10, corresponding to public_key versions 1.16 to 1.20.3 and 1.17.1.2, and ssl versions 11.2 to 11.5.4 and 11.2.12.7.

A network-based attacker (AV:N) with no privileges (PR:N) can exploit this via interception or control of OCSP responses, forging them by creating a self-signed certificate with a matching issuer name and OCSPSigning EKU to mark revoked certificates as valid. Exploitation requires high complexity (AC:H) but has no user interaction (UI:N), with a CVSS v3.1 base score of 7.4 (C:H/I:H/A:N/S:U). SSL/TLS clients using OCSP stapling may accept connections to servers with revoked certificates, enabling transmission of sensitive data to compromised servers. Applications directly invoking public_key:pkix_ocsp_validate/5 face similar risks depending on their OCSP usage context.

Advisories and patches, detailed in the Erlang CNA report, GitHub security advisory GHSA-gxrm-pf64-99xm, and OSV entry, recommend upgrading to fixed OTP releases such as 28.4.2 or 27.3.4.10 (with corresponding public_key 1.20.3/1.17.1.2 and ssl 11.5.4/11.2.12.7). Relevant patches are available in GitHub commits 49033a6d93a5be0ee0dce04e1fb8b4ae7de1e0c0 and ac7ff528be857c5d35eb29c7f24106e3a16d4891.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

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.…

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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.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1195 Supply Chain Compromise Initial Access
Adversaries may manipulate products or product delivery mechanisms prior to receipt by a final consumer for the purpose of data or system compromise.
T1557 Adversary-in-the-Middle Credential Access
Adversaries may attempt to position themselves between two or more networked devices using an adversary-in-the-middle (AiTM) technique to support follow-on behaviors such as [Network Sniffing](https://attack.
T1195.002 Compromise Software Supply Chain Initial Access
Adversaries may manipulate application software prior to receipt by a final consumer for the purpose of data or system compromise.
T1542 Pre-OS Boot Stealth
Adversaries may abuse Pre-OS Boot mechanisms as a way to establish persistence on a system.
T1553 Subvert Trust Controls Defense Impairment
Adversaries may undermine security controls that will either warn users of untrusted activity or prevent execution of untrusted programs.
T1553.002 Code Signing Defense Impairment
Adversaries may create, acquire, or steal code signing materials to sign their malware or tools.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-42789Same product: Erlang Erlang\/Otp
CVE-2026-54891Same product: Erlang Erlang\/Otp
CVE-2026-42790Same product: Erlang Erlang\/Otp
CVE-2026-48860Same product: Erlang Erlang\/Otp
CVE-2026-54887Same product: Erlang Erlang\/Otp
CVE-2026-58227Same product: Erlang Erlang\/Otp
CVE-2026-59251Same product: Erlang Erlang\/Otp
CVE-2026-55952Same product: Erlang Erlang\/Otp
CVE-2026-55953Same product: Erlang Erlang\/Otp
CVE-2026-55950Same product: Erlang Erlang\/Otp

Affected Assets

erlang
erlang\/otp
27.0 — 27.3.4.10 · 28.0 — 28.4.2
erlang
erlang\/public key
1.16 — 1.17.1.2 · 1.18 — 1.20.3
erlang
erlang\/ssl
11.2 — 11.2.12.7 · 11.3 — 11.5.4

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 26 hardening rules · 5 OS baselines
Validate
Prove the fix (OWASP ASVS)

Mitigating Controls (NIST 800-53 r5) AI

Requiring cryptographic protection mechanisms forces correct signature verification to be implemented for data protection.

PKI certificate issuance and acquisition under an approved policy establishes the trusted roots and processes needed for correct validation.

Mandating integrity verification tools directly requires proper cryptographic signature checking to detect unauthorized changes.

Protecting session authenticity depends on cryptographic mechanisms whose trust depends on correct certificate validation.

Requiring confidentiality and integrity protection of transmitted data drives use of properly validated certificates in protocols such as TLS.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.AA-03 mostly match
prevents

Certificate-based authentication of users/services/hardware directly depends on correct validation.

PR.DS-01 mostly match
prevents

Digital signatures are explicitly cited to protect integrity of data-at-rest, so proper verification directly mitigates the weakness.

PR.DS-02 mostly match
prevents

Proper certificate validation is a core mechanism for protecting data-in-transit confidentiality and integrity.

PR.PS-06 mostly match
prevents

Secure development practices explicitly include implementing correct certificate validation logic.

ID.RA-09 partial match
prevents

Assessing authenticity/integrity of acquired software often relies on code-signing certificate validation.

PR.AA-04 partial match
prevents

Identity assertions conveyed via certificates require validation to be verified.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

prevents

Requiring issuance and validation of public-key certificates under an approved policy reduces the chance that certificates with improper validation will be trusted.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (3 rules)
  • V-248574 YUM must be configured to prevent the installation of patches, service packs, device drivers, or OL 8 system components that have not been digitally signed using a certificate that is recognized and approved by the organization. prevents CWE-295, CWE-347
  • V-248531 OL 8, for PKI-based authentication, must validate certificates by constructing a certification path (which includes status information) to an accepted trust anchor. prevents CWE-295
  • V-248575 OL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-295, CWE-347
Oracle Linux 9 (2 rules)
  • V-271525 OL 9 must have GPG signature verification enabled for all software repositories. prevents CWE-347
  • V-271523 OL 9 must check the GPG signature of locally installed software packages before installation. prevents CWE-347
RHEL 7 (2 rules)
  • V-204447 The Red Hat Enterprise Linux operating system must prevent the installation of software, patches, service packs, device drivers, or operating system components from a repository without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-295, CWE-347
  • V-204448 The Red Hat Enterprise Linux operating system must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-295, CWE-347
RHEL 8 (2 rules)
  • V-230264 RHEL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components from a repository without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-295, CWE-347
  • V-230265 RHEL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-295
RHEL 9 (1 rule)
  • V-257822 RHEL 9 must have GPG signature verification enabled for all software repositories. prevents CWE-347

References