Trending
CVE-2026-42791

CVE detail

CVE-2026-42791

Improper Certificate Validation vulnerability in Erlang OTP public_key (pubkey_ocsp module) allows forged OCSP responses signed with an expired responder certificate to be accepted as valid. OCSP response verification in pubkey_ocsp:verify_response/5 and pubkey_ocsp:is_authorized_responder/3 in lib/public_key/src/pubkey_ocsp.erl does not check the validity period (notBefore/notAfter) of the OCSP responder certificate. An attacker who has obtained the private key of an expired CA-designated OCSP responder certificate can forge OCSP responses that Erlang/OTP accepts as valid. This affects TLS clients using OCSP stapling via the ssl application: a malicious or compromised server can present a revoked TLS certificate together with a forged OCSP response signed by an expired responder key, and the client will accept the revoked certificate as valid. It also affects applications calling public_key:pkix_ocsp_validate/5 directly, where the impact depends on the use case — server-side client certificate validation using this API may allow authentication bypass with a revoked client certificate. This issue affects OTP from OTP 27.0 before OTP 29.0.1, OTP 28.5.0.1 and OTP 27.3.4.12, corresponding to public_key from 1.16 before 1.21.1, 1.20.3.1 and 1.17.1.3.

CVSS 6.3 · MediumBuzz score 32.5

Buzz score

Why this CVE is surfacing

Buzz score total 32.5

This all-time snapshot uses the same composite formula as Trending across a 30-year evidence window, rather than a current rolling window.

Buzz score components · mention 19.5 · diversity 13.0 · KEV 0.0 · OTX 0.0 · PoC 0.0

Mention score

19.5

6 evidence mentions in the snapshot

Diversity score

13.0

4 sources across 2 categories

KEV score

0.0

No KEV entry observed

OTX score

0.0

0 OTX pulses

PoC score

0.0

0 repos · best confidence N/A

Best PoC traction

Maximum stars on a matched PoC repo

Why it matters now

Mention timeline

Total mentions: 0; within the 30d window
Peak daily: 0; highest bucket

Evidence

Source links by recency

Newest mentions first

6 source links · newest first

https://www.erlang.org/doc/system/versions.html#order-of-versionswww.erlang.org
No excerpt available.
Vendor Advisorywww.erlang.orgMay 27, 2026, 2:16 PM
https://osv.dev/vulnerability/EEF-CVE-2026-42791osv.dev
No excerpt available.
Exploitosv.devMay 27, 2026, 2:16 PM
https://github.com/erlang/otp/security/advisories/GHSA-cjxj-wj6x-3fffgithub.com
No excerpt available.
Exploitgithub.comMay 27, 2026, 2:16 PM
https://github.com/erlang/otp/commit/b3870e02405c709a872b01ba6086065620cdfe76github.com
No excerpt available.
Exploitgithub.comMay 27, 2026, 2:16 PM
https://github.com/erlang/otp/commit/7995f1fdaee3da569bb810358ce0f546471d169bgithub.com
No excerpt available.
Exploitgithub.comMay 27, 2026, 2:16 PM
https://cna.erlef.org/cves/CVE-2026-42791.htmlcna.erlef.org
No excerpt available.
Vendor Advisorycna.erlef.orgMay 27, 2026, 2:16 PM

Exploit code

Public exploit repository references

Public PoC repositories are third-party, potentially unsafe artifacts. Treat their code as untrusted and use it only on authorized systems in an isolated, least-privilege environment. cvebuzz does not execute the code or verify that an exploit works.

0 repository references · best confidence N/A · max 0 stars

No public PoC repositories have been matched yet.

Related records

Similar CVEs

6 related CVEs with shared weakness or product evidence

CVE-2026-42790
Improper Certificate Validation vulnerability in Erlang OTP public_key (pubkey_cert and public_key modules) allows a DNS nameConstraints bypass via subject CommonName fallback in…
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CVE-2026-42789
Improper Following of a Certificate's Chain of Trust vulnerability in Erlang OTP public_key (pubkey_cert module) allows a non-CA certificate to be accepted as an intermediate issu…
CVSS 7.0 · High
11 mentions
CVE-2026-32144
Improper Certificate Validation vulnerability in Erlang OTP public_key (pubkey_ocsp module) allows OCSP designated-responder authorization bypass via missing signature verificatio…
CVSS 7.6 · High
9 mentions
CVE-2020-35733
An issue was discovered in Erlang/OTP before 23.2.2. The ssl application 10.2 accepts and trusts an invalid X.509 certificate chain to a trusted root Certification Authority.
CVSS 7.5 · High
CVE-2026-54342
In epa4all, prior to version 2026-05-20, an attacker on the network path between epa4all and any backend (ePA Aktensystem, Konnektor, IDP, TSS) can present a self-signed TLS certi…
CVSS 8.1 · High
4 mentions
CVE-2026-48021
In epa4all, prior to version 2026-05-20, an attacker who can intercept the TLS connection between epa4all and the ePA backend can complete the VAU handshake with attacker-controll…
CVSS 9.1 · Critical
3 mentions

External lookup

Potential internet exposure

Potential exposure only — not proof of vulnerability.Shodan results indicate potentially internet-exposed products, not confirmed vulnerable systems. They do not confirm that any returned system is vulnerable to CVE-2026-42791.

Product-level CPE searches intentionally omit version fields and NVD version-range or configuration certainty. Verify the exact product version and configuration independently.

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Product CPE queries

Derived from this CVE's existing NVD CPE 2.3 records; the application, operating-system, or hardware part is retained.

cpe:2.3:a:erlang:erlang\/otpSearch this product on Shodan

Exact CVE query

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Metadata

Canonical fields

NVD status

Modified

Published

May 27, 2026

Modified

Jul 24, 2026

Official record

Authoritative NVD record

CVSS vector

CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/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

CWE IDs

Vendor classifications

How this vector reads

CVSS 4.0 base metrics decoded below. This explanation does not recalculate or change the NVD score.

Attack Vector (AV): Network. The vulnerable system can be reached across network boundaries.
Attack Complexity (AC): High. Successful exploitation depends on conditions outside the attacker's control.
Attack Requirements (AT): Present. A prerequisite deployment or execution condition must be present.
Privileges Required (PR): None. The attacker needs no privileges on the vulnerable system.
User Interaction (UI): None. Exploitation does not require a targeted user to act.
Vulnerable System Confidentiality (VC): None. There is no direct impact to this security property.
Vulnerable System Integrity (VI): Low. There is a limited impact to this security property.
Vulnerable System Availability (VA): None. There is no direct impact to this security property.
Subsequent System Confidentiality (SC): Low. There is a limited impact to this security property.
Subsequent System Integrity (SI): Low. There is a limited impact to this security property.
Subsequent System Availability (SA): None. There is no direct impact to this security property.

Optional CVSS v4 metrics remain in the raw vector; only base metrics are expanded here.

Signals

Exploitation indicators

0 stored signals · no KEV · 0 OTX pulses