CVE-2026-87866

mediumpriority · track · 0EPSS 0.002 · 11 %ileDEFRUS
grimoire priorityP3 · Track
Exploitable?
—
no known exploitation
Likely / severe?
0.21% (11th) EPSS
CVSS 5.9 · medium
Is it mine?
4 products
Check your exposure
Who says so?
3 sources
cert_bund · certfr · osv

EPSS · scored 2026-10-27

When built with wolfSSL, curl can successfully validate a pinned public key hash against a key the TLS peer does not possess. During the TLS handshake, wolfSSL validates the connection, but curl's subsequent re-parsing of the same certificate - tricked by a manipulated validity length field - extracts and matches a different embedded key, incorrectly authorizing the pinned public key.

01

cvss

Technical severity, 0–10. One row per scoring source.

5.9
010

base score 0–10 · higher = more severe · hover a vector to decode

v3.15.9mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:Nsecondary · grimoire (LLM-derived)LLM-inferred
02

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-20USLLM-inferredCWE-362USLLM-inferred
03

affected products (4)

Products and version ranges known to be affected.

04

advisories (4)

Vendor and ecosystem advisories describing this.

  • WID-SEC-W-2026-3904cURL: Mehrere SchwachstellenDeutsch2026-10-13csaf · cert_bundDE

    Ein Angreifer kann mehrere Schwachstellen in cURL ausnutzen, um beliebigen Programmcode auszuführen, Sicherheitsmaßnahmen zu umgehen, vertrauliche Informationen offenzulegen, Daten zu manipulieren oder einen Denial-of-Service-Zustand auszulösen.

  • CERTFR-2026-AVI-1307Multiples vulnérabilités dans CurlFrançais2026-10-14vendor · certfrFR
  • CERTFR-2026-AVI-1385Multiples vulnérabilités dans les produits VMwareFrançais2026-10-26vendor · certfrFR
  • CURL-CVE-2026-87866wolfSSL public-key pinning bypass2026-10-14vendor · osvUS

    When built with wolfSSL, curl can successfully validate a pinned public key hash against a key the TLS peer does not possess. During the TLS handshake, wolfSSL validates the connection, but curl's subsequent re-parsing of the same certificate - tricked by a manipulated validity length field - extracts and matches a different embedded key, incorrectly authorizing the pinned public key.

05

sources

Which sources assert this record, and when.

cert_bundcertfrosvNVDCVE.orgMITRE
published 2026-10-20modified 2026-10-22
06

references (3) nvd

External citations — patches, advisories, analysis.

scry

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