CVE-2026-63574: Unbounded allocation from OpenPGP signature and user attribute subpacket lengths
Legion of the Bouncy Castle Inc. · bc-csharp
Fixed in 2.7.0 · Affected: Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 · Exploitation: unlikely (under 1%)
Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.
Higher than 37% of scored CVEs
DescriptionCVE.org
Memory allocation with excessive size value in the OpenPGP signature and user attribute subpacket parsers (SignatureSubpacketsParser.ReadPacket, UserAttributeSubpacketsParser.ReadPacket) in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows a remote, unauthenticated attacker who can supply a crafted OpenPGP public key, certificate or signature to cause a denial of service (OutOfMemoryException or memory exhaustion in the parsing process) via a subpacket header using the five-octet length form, because the declared length was used to size the subpacket buffer with no upper bound and without being compared with the size of the enclosing subpacket area or packet, so a few bytes of input could demand an allocation of up to about 2 GB before any subpacket data was read.
Affected products1
From the CVE record. A product or version that is not listed is unknown, not unaffected.
- Legion of the Bouncy Castle Inc. · bc-csharpbefore 2.7.0
On the Atlas
Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.
- Exploitation
- Unlikely (under 1%). EPSS under 1%, or no score yet.
- CISA KEV
- Not listed
- Public check
- No public nuclei template
- Published
- October 2026
CoverageNo articles yet
No CyberSIXT article names CVE-2026-63574 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.