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.
CVE-2026-63574
This high-severity CVE scores 8.7 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3% (22nd percentile of EPSS-scored CVEs). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
- High severity, but no confirmed exploitation yet
An upstream fix is merged but not yet released — mitigate (WAF / firewall / segmentation) until the release ships, then apply it.
- CVSS v3
- 8.7
- EG Score
- 8.7HIGHmedium confidence
- EG Risk
- 54EG Risk 54/100CISA SSVC
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity87% × 45%Exploitation0% × 40%Automatability100% × 15%CISA SSVC: Track at low or medium mission impact; Attend at high (mission-essential systems).Action: An upstream fix is merged but not yet in a tagged release. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high until it ships, then apply the release. - EPSS PROB
- 0.3%
- EPSS %ILE
- 22nd
- KEV
- Not listed
CISA SSVCTrack at low or medium mission impact; Attend at high (mission-essential systems).
An upstream fix is merged but not yet in a tagged release. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high until it ships, then apply the release.
Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table
Published
October 2, 2026
Last Modified
October 2, 2026
Advisory Details (3)
Auto-updated Oct 2, 2026commit 986fb4892bb3 (bcgit/bc-csharp)
Fix landed in bcgit/bc-csharp commit 986fb4892bb3 — awaiting tagged release
https://github.com/bcgit/bc-csharp/commit/986fb4892bb39f292ba0fd82eba11d2cbc503217commit f51dacf4817d (bcgit/bc-csharp)
Fix landed in bcgit/bc-csharp commit f51dacf4817d — awaiting tagged release
https://github.com/bcgit/bc-csharp/commit/f51dacf4817d9ea10d0a9841f72fac3655c65483CVE 2026 63574 · bcgit/bc-csharp Wiki · GitHub
https://github.com/bcgit/bc-csharp/wiki/CVE-2026-63574Vendor Advisories for CVE-2026-63574(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 14× in last 7d / 14× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-10-04 05:07 UTCGHSA enrichment
- 2026-10-03 18:13 UTCEG score recompute
- 2026-10-03 18:13 UTCGHSA enrichment
- 2026-10-03 14:26 UTCEPSS rescore
- 2026-10-03 07:14 UTCGHSA enrichment
- 2026-10-02 20:20 UTCEG score recompute
- 2026-10-02 20:20 UTCGHSA enrichment
- 2026-10-02 19:36 UTCEG score recompute
- 2026-10-02 19:36 UTCGHSA enrichment
- 2026-10-02 17:56 UTCEPSS rescore
- 2026-10-02 14:45 UTCGHSA enrichment
- 2026-10-02 08:27 UTCEG score recompute
- 2026-10-02 07:31 UTCEG score recompute
- 2026-10-02 07:30 UTCMITRE cvelistV5first tracked
Related CVEs(same CWE)
Frequently asked(5)
What is CVE-2026-63574?
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Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-63574
Is Your Infrastructure Affected by CVE-2026-63574?
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