In Bouncy Castle for Java before 1.86, validation of an MLS (RFC 9420) external commit's proposal list, org.bouncycastle.mls.protocol.Group.validateExternalCachedProposals, counted the proposals by type and bounded the removed leaf index but never established that the removed leaf had anything to do with the joiner. RFC 9420 sec. 12.2 permits at most one Remove proposal in an external commit, with which the joiner removes an old version of themselves, and requires that where one is present the LeafNode in the commit's path field meet the criteria it would have to meet in an Update for the removed leaf, in particular that its credential present identifiers acceptable for the removed participant. The ordinary proposal-list validator's self-remove rule is deliberately not applied on this path, because a resync commit legitimately removes a leaf the joiner owns, but nothing was put in its place. Any party holding the group's public GroupInfo, which is precisely what an external joiner is meant to be given, could therefore commit a Remove naming any member's LeafIndex and have every member apply it, evicting that member and taking over their slot in the ratchet tree. The credential check that should have prevented this existed only in the gRPC interop harness and so protected no other caller of the public Group.externalJoin and Group.handle API. An external commit carrying a Remove is now accepted only when the removed leaf's credential is identical to the one in the joiner's own new leaf, on both the sending and the receiving side.
CVE-2026-71890
“—” beside the score: it is equal to the CVSS score beside it.
This high-severity CVE scores 8.7 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2% (16th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.
Also known asEUVD-2026-92006 (ENISA EUVD) · GHSA-jc55-7frr-fv5r (GitHub Security Advisories)Source: ENISA EUVD
- High severity, but no confirmed exploitation yet
A fix is available — apply it.
- CVSS v3
- 8.7
- EG Score
- 8.7HIGHmedium confidence
- EG Risk
- 54EG Risk 54/100
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)Severity87% × 45%Impact severity (EG Severity): CVSS 8.7 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.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: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high. - EPSS PROB
- 0.2%
- EPSS %ILE
- 16th
- 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 (8.7): severity, escalated by confirmed exploitation. This CVE's 8.7 is its impact severity (EG Severity), not escalated.
- EG Severity
- 8.7 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 2026-11-02). 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.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).
A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
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.
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 3, 2026
Last Modified
October 6, 2026
Advisory Details (2)
Auto-updated Oct 3, 2026commit 7e8bb10eb90b (bcgit/bc-java)
Fix landed in bcgit/bc-java commit 7e8bb10eb90b — awaiting tagged release
https://github.com/bcgit/bc-java/commit/7e8bb10eb90baddf3f10b8679f627462b9522d24CVE‐2026‐71890 · bcgit/bc-java Wiki · GitHub
https://github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%9071890Vendor Advisories for CVE-2026-71890(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)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| bouncycastle | 1.72-2 ... 1.86-1 (6 versions) |
| — |
Debian:13(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| bouncycastle | 1.80-3, 1.86-1 |
| — |
Debian:14(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| bouncycastle | 1.80-3 |
| — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 11× in last 7d / 71× 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.
- 2026-11-03 16:49 UTCEPSS rescoreEPSS 0.2% · 16th percentile
- 2026-11-03 15:24 UTCEG score recompute
- 2026-11-03 15:24 UTCGHSA enrichmentGHSA-jc55-7frr-fv5r · GitHub severity HIGH
- 2026-11-02 16:46 UTCEPSS rescoreEPSS 0.2% · 16th percentile
- 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.2% · 16th percentile
- 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.2% · 16th percentile
- 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.2% · 16th percentile
- 2026-10-29 16:34 UTCEPSS rescoreEPSS 0.2% · 16th percentile
- 2026-10-28 16:33 UTCEPSS rescoreEPSS 0.2% · 16th percentile
- 2026-10-27 21:08 UTCEG score recompute
- 2026-10-27 21:08 UTCGHSA enrichmentGHSA-jc55-7frr-fv5r · GitHub severity HIGH
- 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.2% · 16th percentile
- 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.2% · 16th percentile
- 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.2% · 16th percentile
- 2026-10-25 14:07 UTCEG score recompute
- 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-10-22 11:53 UTCEG score recompute
- 2026-10-22 11:53 UTCGHSA enrichmentGHSA-jc55-7frr-fv5r · GitHub severity HIGH
- 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-10-20 08:44 UTCEG score recompute
- 2026-10-20 08:44 UTCGHSA enrichmentGHSA-jc55-7frr-fv5r · GitHub severity HIGH
- 2026-10-19 16:33 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.2% · 15th percentile
Show 54 moreShow fewer
- 2026-10-18 03:16 UTCEG score recompute
- 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-10-16 16:44 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-10-13 08:24 UTCEG score recompute
- 2026-10-13 08:24 UTCGHSA enrichmentGHSA-jc55-7frr-fv5r · GitHub severity HIGH
- 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-10-12 15:42 UTCEG score recompute
- 2026-10-11 19:28 UTCEG score recompute
- 2026-10-11 18:49 UTCGHSA enrichmentGHSA-jc55-7frr-fv5r · GitHub severity HIGH
- 2026-10-11 16:43 UTCEG score recompute
- 2026-10-11 14:03 UTCEG score recompute
- 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-10-11 07:33 UTCGHSA enrichmentGHSA-jc55-7frr-fv5r · GitHub severity HIGH
- 2026-10-10 20:17 UTCEG score recompute
- 2026-10-10 20:17 UTCGHSA enrichmentGHSA-jc55-7frr-fv5r · GitHub severity HIGH
- 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-10-10 09:00 UTCGHSA enrichmentGHSA-jc55-7frr-fv5r · GitHub severity HIGH
- 2026-10-09 21:44 UTCEG score recompute
- 2026-10-09 21:44 UTCGHSA enrichmentGHSA-jc55-7frr-fv5r · GitHub severity HIGH
- 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-10-09 10:27 UTCGHSA enrichmentGHSA-jc55-7frr-fv5r · GitHub severity HIGH
- 2026-10-08 23:10 UTCEG score recompute
- 2026-10-08 23:10 UTCGHSA enrichmentGHSA-jc55-7frr-fv5r · GitHub severity HIGH
- 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-10-08 11:54 UTCGHSA enrichmentGHSA-jc55-7frr-fv5r · GitHub severity HIGH
- 2026-10-08 00:38 UTCEG score recompute
- 2026-10-08 00:38 UTCGHSA enrichmentGHSA-jc55-7frr-fv5r · GitHub severity HIGH
- 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-10-07 13:23 UTCGHSA enrichmentGHSA-jc55-7frr-fv5r · GitHub severity HIGH
- 2026-10-07 02:07 UTCEG score recompute
- 2026-10-07 02:07 UTCGHSA enrichmentGHSA-jc55-7frr-fv5r · GitHub severity HIGH
- 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-10-06 14:51 UTCGHSA enrichmentGHSA-jc55-7frr-fv5r · GitHub severity HIGH
- 2026-10-06 03:43 UTCEG score recompute
- 2026-10-06 03:43 UTCGHSA enrichmentGHSA-jc55-7frr-fv5r · GitHub severity HIGH
- 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-10-05 16:28 UTCEG score recompute
- 2026-10-05 16:28 UTCGHSA enrichmentGHSA-jc55-7frr-fv5r · GitHub severity HIGH
- 2026-10-05 16:11 UTCEG score recompute
- 2026-10-05 16:11 UTCGHSA enrichmentGHSA-jc55-7frr-fv5r · GitHub severity HIGH
- 2026-10-05 06:33 UTCEG score recompute
- 2026-10-05 06:33 UTCGHSA enrichmentGHSA-jc55-7frr-fv5r · GitHub severity HIGH
- 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-10-04 19:17 UTCGHSA enrichmentGHSA-jc55-7frr-fv5r · GitHub severity HIGH
- 2026-10-04 08:01 UTCGHSA enrichmentGHSA-jc55-7frr-fv5r · GitHub severity HIGH
- 2026-10-03 20:43 UTCEG score recompute
- 2026-10-03 20:43 UTCGHSA enrichmentGHSA-jc55-7frr-fv5r · GitHub severity HIGH
- 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-10-03 09:25 UTCEG score recompute
- 2026-10-03 09:04 UTCEG score recomputeFirst assessed: 8.7 HIGH
- 2026-10-03 09:04 UTCMITRE cvelistV5first tracked
Related CVEs(same product + same CWE)
Same product
10 shownDebian:12:bouncycastle
Frequently asked(5)
What is CVE-2026-71890?
When was the CVE record for CVE-2026-71890 published?
Is CVE-2026-71890 actively exploited?
What is the CVSS score of CVE-2026-71890?
How do I remediate CVE-2026-71890?
Dependency Blast Radius
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