High Cryptography

CVE-2026-42784 — Sequoia-openpgp: sequoia-openpgp: cryptographic integrity compromise via key flag confusion

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.

Published Sep 16, 2026 · Updated Oct 15, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories · CNA: redhat

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.3% (30-day exploitation probability)+3
Technical severity (high)+6

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.31%

ahead of 23% of scored CVEs · Oct 15, 2026

Affects

Red Hat

Confidential Compute Attestation and 9 more

CVSS base

7.4

High · 3 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation

None

none · proof-of-concept · active

Automatable

can an attacker script the kill-chain steps

Technical impact

Partial

partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Red Hat Confidential Compute Attestation, Red Hat Hardened Images, Red Hat Red Hat Ansible Automation Platform 2…).
The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Exploitation requires user interaction: tighten email/web filtering and warn affected users.
Search available logs for exploit probes matching the vulnerability class (cryptography), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Red Hat	Confidential Compute Attestation	versions not specified by the source	Vulnerable	CVE Program (cve.org) e CISA ADP
Red Hat	Hardened Images	versions not specified by the source	Vulnerable	CVE Program (cve.org) e CISA ADP
Red Hat	Red Hat Ansible Automation Platform 2	versions not specified by the source	Vulnerable	CVE Program (cve.org) e CISA ADP
Red Hat	Red Hat Ansible Automation Platform 2.6 for RHEL 9	versions not specified by the source	Vulnerable	CVE Program (cve.org) e CISA ADP
Red Hat	Red Hat Cost Management On-Premise 1	versions not specified by the source	Vulnerable	CVE Program (cve.org) e CISA ADP
Red Hat	Red Hat Enterprise Linux 10	versions not specified by the source	Vulnerable	CVE Program (cve.org) e CISA ADP
Red Hat	Red Hat Enterprise Linux 9	versions not specified by the source	Vulnerable	CVE Program (cve.org) e CISA ADP
Red Hat	Red Hat OpenShift Container Platform 4	versions not specified by the source	Vulnerable	CVE Program (cve.org) e CISA ADP
Red Hat	Red Hat Satellite 6	versions not specified by the source	Vulnerable	CVE Program (cve.org) e CISA ADP
Red Hat	Red Hat Trusted Profile Analyzer	versions not specified by the source	Vulnerable	CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Network

Attack complexity

Low

Privileges required

None

User interaction

Required

Scope

Changed

Confidentiality

None

Integrity

High

Availability

None

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
7.4	CVSS 3.1	High	2.8	4.0	secalert@redhat.com via NIST National Vulnerability Database
7.4	CVSS 3.1	High	—	—	GitHub, Inc. via GitHub Security Advisories
7.4	CVSS 3.1	High	—	—	redhat via CVE Program (cve.org) e CISA ADP

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:H/A:N (score shown at the top: secalert@redhat.com)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-347 · Improper Verification of Cryptographic Signature

Other CVEs with this weakness →

EPSS over time FIRST

Oct 13, 2026 → Oct 15, 2026 · 3 reading(s) · max 0.31%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
Check TLS negotiations and unexpected certificates in the component’s traffic.

web/proxy/WAF logsnetwork IDS/IPS

Timeline

What happened to this CVE, newest first.

2026
Affected products removed · 1
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
Affected products added · red hat/red hat hardened images
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
Affected products added · red hat/red hat ansible automation platform 2.6 for rhel 9, red hat/red hat enterprise linux 10, red hat/red hat enterpr
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 13, 2026
CVSS changed · 7.4
Oct 13, 2026 · NIST National Vulnerability Database
Source status changed · → Awaiting Analysis
Oct 13, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 13, 2026 · NIST National Vulnerability Database
CVE published
Sep 16, 2026 · redhat

Source activity

Repeated readings are counted rather than listed.

1× References added · Oct 15, 2026 – Oct 15, 2026
1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

12 on the record

access.redhat.com/errata/RHSA-2026:42902
vendor-advisory, x_refsource_REDHAT, NIST National Vulnerability Database
access.redhat.com/security/cve/CVE-2026-42784
vdb-entry, x_refsource_REDHAT, NIST National Vulnerability Database
bugzilla.redhat.com/show_bug.cgi
issue-tracking, x_refsource_REDHAT, NIST National Vulnerability Database
github.com/advisories/GHSA-g33h-rrj9-75qv
GitHub Security Advisories
nvd.nist.gov/vuln/detail/CVE-2026-42784
GitHub Security Advisories
access.redhat.com/errata/RHSA-2026:76735
vendor-advisory, x_refsource_REDHAT, NIST National Vulnerability Database
access.redhat.com/errata/RHSA-2026:42078
vendor-advisory, x_refsource_REDHAT, NIST National Vulnerability Database
access.redhat.com/errata/RHSA-2026:76733
vendor-advisory, x_refsource_REDHAT, NIST National Vulnerability Database
access.redhat.com/errata/RHSA-2026:76734
vendor-advisory, x_refsource_REDHAT, NIST National Vulnerability Database
access.redhat.com/errata/RHSA-2026:79357
vendor-advisory, x_refsource_REDHAT, NIST National Vulnerability Database
access.redhat.com/errata/RHSA-2026:34160
vendor-advisory, x_refsource_REDHAT, NIST National Vulnerability Database
access.redhat.com/errata/RHSA-2026:76737
vendor-advisory, x_refsource_REDHAT, NIST National Vulnerability Database

Elsewhere on this site

Red Hat
every CVE for this vendor

Cryptography
same class

CWE-347
other pages naming this weakness

Related CVEs (same products)

Medium CVE-2026-109131 Ansible-ui: ansible-ui: stored xss via unsafe javascript url scheme in hub collection module documentation (formatparturl) 4h
High CVE-2026-92982 Ansible-operator-plugins: ansible operator plugins: arbitrary code execution via jinja2 template injection 7h
Medium CVE-2026-110924 Openssh: openssh: gssapi delegated credentials can be stored after a failed authentication 9h
Medium CVE-2026-110927 Openssh: openssh: a compressed payload can expand past the maximum packet size 9h
Medium CVE-2026-110923 Openssh: openssh: sftp can write outside the destination directory from a server-supplied path 17h
Medium CVE-2026-110926 Openssh: openssh: shared lz77 compression dictionary leaks plaintext across channels 17h

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No fixed version, patch or mitigation documented.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-42784 is "Sequoia-openpgp: sequoia-openpgp: cryptographic integrity compromise via key flag confusion", rated High. It affects Confidential Compute Attestation (Red Hat); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.4 describes technical severity. EPSS 0.31% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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