CVE-2026-42784
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.31%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 3.1
- 7.4 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:H/A:N
- EPSS
- 0.31% probability · 24th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-347
- Source
- secalert@redhat.com
EPSS 0.3% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://access.redhat.com/errata/RHSA-2026:34160
- https://access.redhat.com/errata/RHSA-2026:42078
- https://access.redhat.com/errata/RHSA-2026:42902
- https://access.redhat.com/errata/RHSA-2026:76733
- https://access.redhat.com/errata/RHSA-2026:76734
- https://access.redhat.com/errata/RHSA-2026:76735
- https://access.redhat.com/errata/RHSA-2026:76737
- https://access.redhat.com/errata/RHSA-2026:79357
- https://access.redhat.com/security/cve/CVE-2026-42784
- https://bugzilla.redhat.com/show_bug.cgi?id=2464122
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.