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CVE Record

CVE-2026-32144: 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 until OTP 28.4.2 and 27.3.4.10 corresponding to public_key from 1.16 until 1.20.3 and 1.17.1.2, and ssl from 11.2 until 11.5.4 and 11.2.12.7.

HighCVSS 7.6Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

Erlang/OTP could accept a forged OCSP status response from a fake designated responder. A client relying on OCSP stapling might treat a revoked TLS certificate as valid, exposing sensitive traffic to a compromised or impersonated server.

Executive priority

Treat as high priority for Erlang-based systems that rely on TLS certificate revocation checks. The issue can undermine a key trust control, but evidence in the supplied sources does not support emergency active-exploitation handling.

Technical view

In public_key:pkix_ocsp_validate/5, pubkey_ocsp:is_authorized_responder/3 checked issuer name and OCSPSigning EKU but did not verify the responder certificate signature chain to the issuing CA. This impacts OTP 27.0 through fixed 27.3.4.10/28.4.2 lines and related public_key and ssl versions.

Likely exposure

Exposure is most likely in Erlang/OTP TLS clients that validate OCSP stapling, and applications directly calling public_key:pkix_ocsp_validate/5. Server-side risk depends on whether clients enforce OCSP status through affected OTP libraries.

Exploitation context

The bundle does not show CISA KEV listing or active exploitation. Exploitation requires an attacker able to intercept or control OCSP responses and a victim path where OCSP validation influences trust decisions.

Researcher notes

Focus review on OCSP responder authorization and certificate path validation. The core flaw is authorization based on issuer-name match and EKU without cryptographic verification that the CA signed the responder certificate.

Mitigation direction

  • Upgrade Erlang/OTP to vendor fixed releases 27.3.4.10 or 28.4.2 where applicable.
  • Update public_key and ssl package versions consistent with the fixed OTP release line.
  • Review Erlang advisory GHSA-gxrm-pf64-99xm for release-specific guidance.
  • If immediate upgrade is blocked, assess disabling reliance on affected OCSP validation paths.
  • Prioritize internet-facing clients handling sensitive data or high-trust TLS connections.

Validation and detection

  • Inventory Erlang/OTP runtime versions across production, CI images, and containers.
  • Identify use of public_key:pkix_ocsp_validate/5 and OCSP stapling in TLS clients.
  • Confirm public_key and ssl versions are outside the affected ranges.
  • Review dependency locks and base images for embedded Erlang/OTP packages.
  • Check vendor advisories for distribution-specific status, especially Red Hat packages.
Prepared
Confidence
high
Sources
9

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

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cwe · low confidence lookup

CWE-295: Exact CWE lookup

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cwe · low confidence lookup

CWE-347: Exact CWE lookup

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description · low confidence lookup

Privilege behavior lookup

The CVE wording references privilege impact, so privilege escalation and authorization behavior review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

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cve · low confidence lookup

CVE-2026-32144 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
High
CVSS
7.6 (4.0)
Known Exploited
No
Published

Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:L/SI:L/SA:N

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

2CVSS vectors
5Timeline events
2ADP providers
10Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: total

CVSS vector scores

2 official scores

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
7.6CVSS 4.0HighCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:L/SI:L/SA:N——EEF
7.4CVSS 3.1HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N2.25.2redhat-SADP

Vulnerability scoring details

Base CVSS 4.0 score

7.6High
CVSS 4.0 vector shape for CVE-2026-32144Attack VectorAttack ComplexityAttack RequirementsPrivileges RequiredUser InteractionVS ConfidentialityVS IntegrityVS AvailabilitySS ConfidentialitySS IntegritySS Availability

Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:L/SI:L/SA:N

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Attack Requirements
NonePresent
Privileges Required
NoneLowHigh
User Interaction
NonePassiveActive
VS Confidentiality
HighLowNone
VS Integrity
HighLowNone
VS Availability
HighLowNone
SS Confidentiality
HighLowNone
SS Integrity
HighLowNone
SS Availability
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. ADP timelineredhat-SADP

    Made public.

  3. CVE publishedCVE Program

    The CVE record was published.

  4. ADP timelineredhat-SADP

    Reported to Red Hat.

  5. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc
redhat-SADPErlang OTP: Erlang OTP public_key: OCSP authorization bypass and information disclosure due to missing signature verification
other:Red Hat severity ratingcvssV3_1
  • 2026-04-07T13:00:56.836Z: Reported to Red Hat.
  • 2026-04-07T12:28:00.767Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
ErlangOTPpublic_key, 1.16unknown
ErlangOTPssl, 11.2unknown
ErlangOTPerlang/otp, 27.0, 601a012837ea0a5c8095bf24223132824177124dunknown
Weakness

CWE details

CWE-295CWE-347

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-295 · source CWE mapping

Improper Certificate Validation

Improper Certificate Validation represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs
CWE-347 · source CWE mapping

Improper Verification of Cryptographic Signature

Improper Verification of Cryptographic Signature represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs