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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 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.

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 can wrongly trust a forged OCSP response that says a revoked TLS certificate is still valid. An attacker must be able to intercept or control OCSP responses. Affected clients could then connect to compromised servers and disclose sensitive data despite certificate revocation.

Executive priority

Treat as a high-priority trust-control issue for affected Erlang TLS clients, especially systems handling credentials or sensitive data. Accelerate inventory and upgrades where OCSP is used. Immediate emergency response is not supported by the supplied evidence because active exploitation is not reported.

Technical view

public_key:pkix_ocsp_validate/5 checks a designated responder certificate’s issuer name and OCSPSigning EKU but fails to verify its CA signature. A self-signed responder certificate with matching metadata can therefore authorize forged OCSP status. The flaw affects pubkey_ocsp:is_authorized_responder/3 and relevant public_key and ssl releases.

Likely exposure

Exposure exists where OTP TLS clients validate OCSP stapling or applications directly call public_key:pkix_ocsp_validate/5. The bundle identifies OTP releases beginning with 27.0 before the listed fixed branch releases. Systems not using these OCSP validation paths may not be practically exposed.

Exploitation context

Exploitation requires an attacker to intercept or control OCSP responses and present a crafted responder certificate. Successful abuse can make revoked certificates appear valid. The bundle marks this CVE as absent from KEV and provides no evidence of active exploitation.

Researcher notes

The authorization failure is narrower than general certificate validation: the responder certificate’s cryptographic relationship to the issuing CA is not verified. Impact depends on OCSP use and attacker control of response delivery. The supplied version metadata is branch-specific; validate exact package status against the Erlang advisory and downstream vendor records.

Mitigation direction

  • Upgrade OTP to fixed releases 28.4.2 or 27.3.4.10, as appropriate for the deployed branch.
  • Ensure corresponding public_key and ssl components meet the fixed versions identified by the vendor.
  • Prioritize Internet-facing clients and applications that validate OCSP responses directly.
  • Consult the Erlang advisory before applying branch-specific upgrades or backports.

Validation and detection

  • Inventory deployed OTP, public_key, and ssl versions across applications and runtime images.
  • Identify TLS clients using OCSP stapling and direct callers of public_key:pkix_ocsp_validate/5.
  • Confirm upgraded environments reject unauthorized designated-responder certificates in an approved test environment.
  • Verify package provenance and that vendor patches are present in maintained downstream builds.
Prepared
Confidence
high
Sources
6

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

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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