CVE-2026-71886

HIGHPre-NVD 8.28.2
EchelonGraph scoreMEDIUM confidence

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

This high-severity CVE scores 8.2 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2% (5th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from a secondary CVSS source
Sources: EPSS, a secondary CVSS source
Trending — 3 sources updated this week

Also known asEUVD-2026-92002 (ENISA EUVD) · GHSA-7hrr-mw36-px4x (GitHub Security Advisories)Source: ENISA EUVD

8.2EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 8.2Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

In Bouncy Castle for Java before 1.86, the high-level OpenPGP certificate API accepted a third-party certification or trust delegation from any component key of the issuing certificate, without requiring that component to have been granted the authority to certify. OpenPGPCertificate.getCertificationBy() and getDelegationBy() resolve a third-party signature by matching its issuer key identifier against every key of the third-party certificate, then verify the issuing component's binding chain and the signature itself; nothing checked that the issuing component carried the RFC 9580 sec. 5.2.3.29 certification key flag (CERTIFY_OTHER) when the signature was created. A subkey bound only with SIGN_DATA - the online signing subkey of exactly the offline-primary arrangement those key flags exist to express - could therefore issue a positive User ID certification over an attacker-controlled identity, or a full-trust depth-one direct-key delegation of introducer trust, and the API returned it as a valid signature chain attributed to the third-party certificate. An application treating getCertificationBy(...).isValid() or getDelegationBy(...) as an identity or trusted-introducer decision would attribute the attacker's assertion to the offline primary key. The same held for a legacy RSA subkey bound only for encryption, whose algorithm is nonetheless able to sign. This does not forge the primary key's signature or recover any private key; it promotes an already-compromised restricted subkey to the primary key's identity-issuing authority, defeating the containment the key-flag separation provides. A third-party certification or delegation is now attributed to the issuing certificate only when the component key that made it is the primary key, or is a subkey holding CERTIFY_OTHER when the signature was created, so certification-capable subkeys continue to be accepted; primary keys are accepted whatever their key flags say, since a primary key is certification-capable by construction and certificates carrying no key flags subpacket at all are common. Third-party revocations are deliberately outside the rule, since declining to honour one would keep trust alive rather than withdraw it.

CVSS v3
8.2
EG Score
8.2HIGHmedium confidence
EG Risk
37
EG Risk 37/100

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)
Severity82% × 45%
Impact severity (EG Severity): CVSS 8.2 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.2% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at every mission impact level.
Exploitation none (CISA Vulnrichment) · Automatable no (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: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.2%
EPSS %ILE
5th
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 (8.2): severity, escalated by confirmed exploitation. This CVE's 8.2 is its impact severity (EG Severity), not escalated.

EG Severity
8.2 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.a secondary CVSS source · CVSS v3.0 or v3.1
EG Likelihood
0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-27). 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 every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.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 every mission impact level.

A fix is available. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (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)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (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 3, 2026

Last Modified

October 6, 2026

Advisory Details (2)

Auto-updated Oct 3, 2026
Patch available. Sources: github_commit.
GitHub commit

commit f0d5c8535aef (bcgit/bc-java)

Fix landed in bcgit/bc-java commit f0d5c8535aef — awaiting tagged release

https://github.com/bcgit/bc-java/commit/f0d5c8535aeff3f34b7b6b6289ee78c2ea36a3fb
Web page

CVE‐2026‐71886 · bcgit/bc-java Wiki · GitHub

https://github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%9071886

Vendor Advisories for CVE-2026-71886(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(3 across 3 ecosystems)
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
bouncycastle1.72-2 ... 1.86-1 (6 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
bouncycastle1.80-3, 1.86-1
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
bouncycastle1.80-3
  • every version up to 1.86-1: fixed in 1.86-1
—

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 9× in last 7d / 69× 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 0.2% · 5th percentile
  2. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  3. 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  4. 2026-10-29 16:34 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  5. 2026-10-28 16:33 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  6. 2026-10-27 21:08 UTCEG score recompute
  7. 2026-10-27 21:08 UTCGHSA enrichmentGHSA-7hrr-mw36-px4x · GitHub severity HIGH
  8. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  9. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  10. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  11. 2026-10-25 14:07 UTCEG score recompute
  12. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  13. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  14. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  15. 2026-10-22 11:32 UTCEG score recompute
  16. 2026-10-22 11:32 UTCGHSA enrichmentGHSA-7hrr-mw36-px4x · GitHub severity HIGH
  17. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  18. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  19. 2026-10-19 17:10 UTCEG score recompute
  20. 2026-10-19 17:10 UTCGHSA enrichmentGHSA-7hrr-mw36-px4x · GitHub severity HIGH
  21. 2026-10-19 16:33 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  22. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  23. 2026-10-18 03:16 UTCEG score recompute
  24. 2026-10-16 16:44 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  25. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.2% · 5th percentile
Show 48 more
  1. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  2. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  3. 2026-10-13 08:24 UTCEG score recompute
  4. 2026-10-13 08:24 UTCGHSA enrichmentGHSA-7hrr-mw36-px4x · GitHub severity HIGH
  5. 2026-10-12 15:42 UTCEG score recompute
  6. 2026-10-11 19:28 UTCEG score recompute
  7. 2026-10-11 18:28 UTCGHSA enrichmentGHSA-7hrr-mw36-px4x · GitHub severity HIGH
  8. 2026-10-11 16:43 UTCEG score recompute
  9. 2026-10-11 14:03 UTCEG score recompute
  10. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  11. 2026-10-11 06:08 UTCEG score recompute
  12. 2026-10-11 06:07 UTCGHSA enrichmentGHSA-7hrr-mw36-px4x · GitHub severity HIGH
  13. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  14. 2026-10-10 17:51 UTCGHSA enrichmentGHSA-7hrr-mw36-px4x · GitHub severity HIGH
  15. 2026-10-10 05:36 UTCEG score recompute
  16. 2026-10-10 05:36 UTCGHSA enrichmentGHSA-7hrr-mw36-px4x · GitHub severity HIGH
  17. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  18. 2026-10-09 17:20 UTCGHSA enrichmentGHSA-7hrr-mw36-px4x · GitHub severity HIGH
  19. 2026-10-09 05:02 UTCEG score recompute
  20. 2026-10-09 05:02 UTCGHSA enrichmentGHSA-7hrr-mw36-px4x · GitHub severity HIGH
  21. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  22. 2026-10-08 16:46 UTCGHSA enrichmentGHSA-7hrr-mw36-px4x · GitHub severity HIGH
  23. 2026-10-08 04:20 UTCEG score recompute
  24. 2026-10-08 04:20 UTCGHSA enrichmentGHSA-7hrr-mw36-px4x · GitHub severity HIGH
  25. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  26. 2026-10-07 16:04 UTCGHSA enrichmentGHSA-7hrr-mw36-px4x · GitHub severity HIGH
  27. 2026-10-07 03:08 UTCEG score recompute
  28. 2026-10-07 03:08 UTCGHSA enrichmentGHSA-7hrr-mw36-px4x · GitHub severity HIGH
  29. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  30. 2026-10-06 14:52 UTCGHSA enrichmentGHSA-7hrr-mw36-px4x · GitHub severity HIGH
  31. 2026-10-06 04:44 UTCEG score recompute
  32. 2026-10-06 04:44 UTCGHSA enrichmentGHSA-7hrr-mw36-px4x · GitHub severity HIGH
  33. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  34. 2026-10-05 16:28 UTCEG score recompute
  35. 2026-10-05 16:28 UTCGHSA enrichmentGHSA-7hrr-mw36-px4x · GitHub severity HIGH
  36. 2026-10-05 16:11 UTCEG score recompute
  37. 2026-10-05 16:11 UTCGHSA enrichmentGHSA-7hrr-mw36-px4x · GitHub severity HIGH
  38. 2026-10-05 10:27 UTCEG score recompute
  39. 2026-10-05 10:27 UTCGHSA enrichmentGHSA-7hrr-mw36-px4x · GitHub severity HIGH
  40. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  41. 2026-10-04 22:12 UTCGHSA enrichmentGHSA-7hrr-mw36-px4x · GitHub severity HIGH
  42. 2026-10-04 09:57 UTCGHSA enrichmentGHSA-7hrr-mw36-px4x · GitHub severity HIGH
  43. 2026-10-03 21:41 UTCEG score recompute
  44. 2026-10-03 21:41 UTCGHSA enrichmentGHSA-7hrr-mw36-px4x · GitHub severity HIGH
  45. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  46. 2026-10-03 09:25 UTCEG score recompute
  47. 2026-10-03 08:57 UTCEG score recomputeFirst assessed: 8.2 HIGH
  48. 2026-10-03 08:54 UTCMITRE cvelistV5first tracked

Related CVEs(same product + same CWE)

Frequently asked(5)

What is CVE-2026-71886?
CVE-2026-71886 is a high-severity vulnerability; its CVE record was published on October 3, 2026. In Bouncy Castle for Java before 1.86, the high-level OpenPGP certificate API accepted a third-party certification or trust delegation from any component key of the issuing certificate, without requiring that component to have been granted the authority to certify.…
When was the CVE record for CVE-2026-71886 published?
The CVE record for CVE-2026-71886 was published on October 3, 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 6, 2026; the record at its source may have been updated since.
Is CVE-2026-71886 actively exploited?
CVE-2026-71886 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (5th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-71886?
CVE-2026-71886 has a CVSS base score of 8.2 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-71886?
A fix for CVE-2026-71886 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-71886 are linked in the Vendor Advisories panel on this page.

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