CVE-2026-63574

HIGHNVD 7.57.5
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to NVD's CVSS score.

This high-severity CVE scores 7.5 under NVD CVSS v3. EPSS exploit probability: 0.4% (36th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from NVD CVSS v3
Sources: EPSS, NVD CVSS v3
Trending — 4 sources updated this week

Also known asEUVD-2026-91225 (ENISA EUVD) · GHSA-576x-9vpc-g3jj (GitHub Security Advisories)Source: ENISA EUVD

7.5EG
EchelonGraph verdictPlan mitigationThe upstream fix is not in a release yet: until the release ships, restrict network exposure of the affected system or apply the vendor's mitigation on your normal schedule at low or medium mission impact and sooner than that at high, then apply it (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 7.5Exploit: None knownExposed services: Not assessed

An upstream fix is merged but not yet released — mitigate (WAF / firewall / segmentation) until the release ships, then apply it.

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.

CVSS v3
7.5
EG Score
7.5HIGHmedium confidence
EG Risk
49
EG Risk 49/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity75% × 45%
Impact severity (EG Severity): CVSS 7.5 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.4% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: An upstream fix is merged but not yet in a tagged release. Until the release ships, restrict network exposure of the affected system or apply the vendor's mitigation on your normal schedule at low or medium mission impact and sooner than that at high, then apply it.
EPSS PROB
0.4%
EPSS %ILE
36th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (7.5): severity, escalated by confirmed exploitation. This CVE's 7.5 is its impact severity (EG Severity), not escalated.

EG Severity
7.5 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.NVD CVSS v3 · CVSS v3.0 or v3.1
EG Likelihood
0.4% within 30 daysSource: FIRST EPSS. FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at low or medium mission impact; Attend at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; 60 days if it is not.No released fix is confirmed on this page, but CISA's timeline does not wait for a fix's release: it starts when an agency identifies the flaw on an asset and updates the CDM Agency and Federal Dashboard, and the directive counts patching, decommissioning the system or another action as remediation. Until a fixed release is applied, mitigate as this page's verdict says.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Attend at high (mission-essential systems).

An upstream fix is merged but not yet in a tagged release. Until the release ships, restrict network exposure of the affected system or apply the vendor's mitigation on your normal schedule at low or medium mission impact and sooner than that at high, then apply it.

Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; 60 days if it is not.

No released fix is confirmed on this page, but CISA's timeline does not wait for a fix's release: it starts when an agency identifies the flaw on an asset and updates the CDM Agency and Federal Dashboard, and the directive counts patching, decommissioning the system or another action as remediation. Until a fixed release is applied, mitigate as this page's verdict says.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

October 2, 2026

Last Modified

October 28, 2026

Advisory Details (3)

Auto-updated Oct 2, 2026
Upstream fix merged — awaiting tagged release. Sources: github_commit.
GitHub commit

commit 986fb4892bb3 (bcgit/bc-csharp)

Fix landed in bcgit/bc-csharp commit 986fb4892bb3 — awaiting tagged release

https://github.com/bcgit/bc-csharp/commit/986fb4892bb39f292ba0fd82eba11d2cbc503217
GitHub commit

commit f51dacf4817d (bcgit/bc-csharp)

Fix landed in bcgit/bc-csharp commit f51dacf4817d — awaiting tagged release

https://github.com/bcgit/bc-csharp/commit/f51dacf4817d9ea10d0a9841f72fac3655c65483
Web page

CVE 2026 63574 · bcgit/bc-csharp Wiki · GitHub

https://github.com/bcgit/bc-csharp/wiki/CVE-2026-63574

Vendor 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 12× in last 7d / 75× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

  1. 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  2. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  3. 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  4. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  5. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  6. 2026-10-28 13:27 UTCEG score recompute▼ 1.20
  7. 2026-10-28 13:26 UTCGHSA enrichmentGHSA-576x-9vpc-g3jj · GitHub severity HIGH
  8. 2026-10-28 13:26 UTCNVD updateCVSS v3 → 7.5
  9. 2026-10-27 21:05 UTCEG score recompute
  10. 2026-10-27 21:05 UTCGHSA enrichmentGHSA-576x-9vpc-g3jj · GitHub severity HIGH
  11. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  12. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  13. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  14. 2026-10-25 14:13 UTCEG score recompute
  15. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  16. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  17. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  18. 2026-10-22 11:54 UTCEG score recompute
  19. 2026-10-22 11:54 UTCGHSA enrichmentGHSA-576x-9vpc-g3jj · GitHub severity HIGH
  20. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  21. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  22. 2026-10-20 09:16 UTCEG score recompute
  23. 2026-10-20 09:16 UTCGHSA enrichmentGHSA-576x-9vpc-g3jj · GitHub severity HIGH
  24. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  25. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
Show 60 more
  1. 2026-10-18 03:23 UTCEG score recompute
  2. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  3. 2026-10-16 16:43 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  4. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  5. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  6. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  7. 2026-10-13 11:58 UTCEG score recompute
  8. 2026-10-13 11:58 UTCGHSA enrichmentGHSA-576x-9vpc-g3jj · GitHub severity HIGH
  9. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  10. 2026-10-12 15:49 UTCEG score recompute
  11. 2026-10-12 00:39 UTCGHSA enrichmentGHSA-576x-9vpc-g3jj · GitHub severity HIGH
  12. 2026-10-11 19:33 UTCEG score recompute
  13. 2026-10-11 16:48 UTCEG score recompute
  14. 2026-10-11 14:10 UTCEG score recompute
  15. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  16. 2026-10-11 13:18 UTCEG score recompute
  17. 2026-10-11 13:18 UTCGHSA enrichmentGHSA-576x-9vpc-g3jj · GitHub severity HIGH
  18. 2026-10-11 02:20 UTCEG score recompute
  19. 2026-10-11 02:19 UTCGHSA enrichmentGHSA-576x-9vpc-g3jj · GitHub severity HIGH
  20. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  21. 2026-10-10 15:21 UTCGHSA enrichmentGHSA-576x-9vpc-g3jj · GitHub severity HIGH
  22. 2026-10-10 04:28 UTCEG score recompute
  23. 2026-10-10 04:27 UTCGHSA enrichmentGHSA-576x-9vpc-g3jj · GitHub severity HIGH
  24. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  25. 2026-10-09 17:33 UTCGHSA enrichmentGHSA-576x-9vpc-g3jj · GitHub severity HIGH
  26. 2026-10-09 06:38 UTCGHSA enrichmentGHSA-576x-9vpc-g3jj · GitHub severity HIGH
  27. 2026-10-08 19:44 UTCEG score recompute
  28. 2026-10-08 19:44 UTCGHSA enrichmentGHSA-576x-9vpc-g3jj · GitHub severity HIGH
  29. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  30. 2026-10-08 07:43 UTCEG score recompute
  31. 2026-10-08 07:43 UTCGHSA enrichmentGHSA-576x-9vpc-g3jj · GitHub severity HIGH
  32. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  33. 2026-10-07 20:48 UTCGHSA enrichmentGHSA-576x-9vpc-g3jj · GitHub severity HIGH
  34. 2026-10-07 09:28 UTCGHSA enrichmentGHSA-576x-9vpc-g3jj · GitHub severity HIGH
  35. 2026-10-06 22:34 UTCEG score recompute
  36. 2026-10-06 22:34 UTCGHSA enrichmentGHSA-576x-9vpc-g3jj · GitHub severity HIGH
  37. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  38. 2026-10-06 11:40 UTCGHSA enrichmentGHSA-576x-9vpc-g3jj · GitHub severity HIGH
  39. 2026-10-06 00:45 UTCEG score recompute
  40. 2026-10-06 00:45 UTCGHSA enrichmentGHSA-576x-9vpc-g3jj · GitHub severity HIGH
  41. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  42. 2026-10-05 13:52 UTCGHSA enrichmentGHSA-576x-9vpc-g3jj · GitHub severity HIGH
  43. 2026-10-05 02:58 UTCEG score recompute
  44. 2026-10-05 02:57 UTCGHSA enrichmentGHSA-576x-9vpc-g3jj · GitHub severity HIGH
  45. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  46. 2026-10-04 16:01 UTCGHSA enrichmentGHSA-576x-9vpc-g3jj · GitHub severity HIGH
  47. 2026-10-04 05:07 UTCGHSA enrichmentGHSA-576x-9vpc-g3jj · GitHub severity HIGH
  48. 2026-10-03 18:13 UTCEG score recompute
  49. 2026-10-03 18:13 UTCGHSA enrichmentGHSA-576x-9vpc-g3jj · GitHub severity HIGH
  50. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  51. 2026-10-03 07:14 UTCGHSA enrichmentGHSA-576x-9vpc-g3jj · GitHub severity HIGH
  52. 2026-10-02 20:20 UTCEG score recompute
  53. 2026-10-02 20:20 UTCGHSA enrichmentGHSA-576x-9vpc-g3jj · GitHub severity HIGH
  54. 2026-10-02 19:36 UTCEG score recompute
  55. 2026-10-02 19:36 UTCGHSA enrichmentGHSA-576x-9vpc-g3jj · GitHub severity HIGH
  56. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  57. 2026-10-02 14:45 UTCGHSA enrichmentGHSA-576x-9vpc-g3jj · GitHub severity HIGH
  58. 2026-10-02 08:27 UTCEG score recompute
  59. 2026-10-02 07:31 UTCEG score recomputeFirst assessed: 8.7 HIGH
  60. 2026-10-02 07:30 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-63574?
CVE-2026-63574 is a high-severity vulnerability; its CVE record was published on October 2, 2026. 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…
When was the CVE record for CVE-2026-63574 published?
The CVE record for CVE-2026-63574 was published on October 2, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of October 28, 2026; the record at its source may have been updated since.
Is CVE-2026-63574 actively exploited?
CVE-2026-63574 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (36th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-63574?
CVE-2026-63574 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-63574?
An upstream fix for CVE-2026-63574 has been merged but is not yet in a tagged release. Until it ships, restrict network exposure of the affected system or apply the vendor's mitigation, then update to the release that contains the fix. The vendor advisories EchelonGraph has for CVE-2026-63574 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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