Vulnerability · CVE-2026-42784
A flaw was found in sequoia-openpgp.
Published Sep 16, 2026 · catalog updated Oct 15, 2026 · A flaw was found
Check if you run it
No confirmed exploitation is on record for CVE-2026-42784. EPSS is 0.31%. Act only if a listed version of A flaw was found is installed.
Gaps on this record
- The stored product name is a package slug. The name on this page is taken from the title (A flaw was found).
- No version range is stored. A customer cannot check an installed version against this record.
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
- Severity
- High7.4
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- 0.31%
- Remediation
- Not established
- Affected products
- See sources for product scope
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.
No affected version ranges are stored yet. Use the vendor advisory before you decide this record does not apply.
How to fix CVE-2026-42784
Recommended remediation
No required-action text, fix commit, or clear fixed-version range is stored yet.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
No confirmed exploitation is on record for CVE-2026-42784. EPSS is 0.31%. Act only if a listed version of A flaw was found is installed.
Which versions are affected?
Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
CWE-347: Improper Verification of Cryptographic Signature. EPSS 0.31%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
Sep 16, 2026 · NIST NVD
Detected
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, com
Oct 15, 2026 · NIST NVD
Updated
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, com
Sources
- CVE.orgVulnerability recordCVE-2026-42784
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2026-42784
30-day exploitation probability 0.3%
first.org - NIST NVDVulnerability recordCVE-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.
nvd.nist.gov
References
Freshness
Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.