Vulnerability record/PUBLISHED/Published Sep 16, 2026 16:56:11 UTC

CVE-2026-42784

A flaw was found in sequoia-openpgp. The library incorrectly infers key flags for older certificates when a key flags subpacket is missing, leading to a discrepancy in how key capabilities are viewed. This key flag confusion allows an attacker to bypass the back-signature check. Consequently, an attacker can illegitimately bind an arbitrary subkey to their own certificate and forge signatures, completely compromising cryptographic integrity.

Base score7.4/ 10

SeverityHighCVSS 3.1

Exploitability / impact

CVSS metric breakdown

Vector-derived attributes

Base severityHigh

Attack vectorNetworkAV

Attack complexityLowAC

Privileges requiredNonePR

User interactionRequiredUI

ScopeChangedS

Confidentiality impactNoneC

Integrity impactHighI

Availability impactNoneA

CVSS vector stringCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:H/A:N

CVSS communicates standardized severity and impact characteristics. It does not establish whether a system is exploitable in your specific environment.

Record context

CVE Numbering Authorityredhat

Last updatedNov 3, 2026 11:47:14 UTC

PublishedSep 16, 2026 16:56:11 UTC

ReservedApr 29, 2026 15:09:53 UTC