CVE-2026-55776

MEDIUMPre-NVD 6.56.5
EchelonGraph scoreMEDIUM confidence

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

This medium-severity CVE scores 6.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.6% (49th 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 weekElevated

Also known asEUVD-2026-78682 (ENISA EUVD) · GHSA-8w8f-r2xv-4q4j (GitHub Security Advisories) · GO-2026-5267 (OSV.dev)Source: ENISA EUVD

6.5EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
CISA-KEV: Not listedEPSS PROB: 0.6%CVSS: 6.5Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

OpenBao is an open source identity-based secrets management system. Prior to 2.5.5, an authenticated OpenBao caller with write access to transit/keys/* could terminate the server process by setting derived to true while the type parameter selected rsa-, ecdsa-, or ed25519. The Transit policy creation path in builtin/logical/transit/backend.go and sdk/helper/keysutil/policy.go could reach an error path that double-unlocked a mutex while handling this invalid asymmetric derived-key combination, causing a panic, no HTTP response, process exit, and denial of service. JSON and HCL key-creation requests can express the triggering combination. This issue is fixed in version 2.5.5.

CVSS v3
6.5
EG Score
6.5MEDIUMmedium confidence
EG Risk
45
EG Risk 45/100

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)
Severity65% × 45%
Impact severity (EG Severity): CVSS 6.5 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation40% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation public PoC (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
0.6%
EPSS %ILE
49th
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 (6.5): severity, escalated by confirmed exploitation. This CVE's 6.5 is its impact severity (EG Severity), not escalated.

EG Severity
6.5 MEDIUMCVSS-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
0.6% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-24). 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; Track* at high (mission-essential systems).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: the SSVC and BOD 26-04 blocks below.

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

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

Exploitation public PoC (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.

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

June 19, 2026

Last Modified

September 29, 2026

Advisory Details (5)

Auto-updated Sep 15, 2026
Patch available. Sources: github, github_pr, github_commit.
GitHub commit

commit db57c62602b2 (openbao/openbao)

Fix landed in openbao/openbao commit db57c62602b2 — awaiting tagged release

https://github.com/openbao/openbao/commit/db57c62602b25da12951f3f0edb888e7c4da61e5
GitHub commit

commit bb17827f3e33 (openbao/openbao)

Fix landed in openbao/openbao commit bb17827f3e33 — awaiting tagged release

https://github.com/openbao/openbao/commit/bb17827f3e33779a10166f7d0e61b191c0facef9
GitHub pull request

Fix panic due to unlock of unlocked mutex in Transit (#3309)

Fix merged in openbao/openbao PR #3312 on 2026-06-17 — awaiting tagged release

https://github.com/openbao/openbao/pull/3312
GitHub pull request

Fix panic due to unlock of unlocked mutex in Transit

Fix merged in openbao/openbao PR #3309 on 2026-06-17 — awaiting tagged release

https://github.com/openbao/openbao/pull/3309
GitHub advisoryMentions a patch (unverified)

OpenBao crashes on Transit engine key creation with derived=true for RSA key types · Advisory · openbao/openbao · GitHub

https://github.com/openbao/openbao/security/advisories/GHSA-8w8f-r2xv-4q4j

Vendor Advisories for CVE-2026-55776(1)

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

Affected Packages

(1 across 1 ecosystem)
Go(1)
PackageVulnerable rangeFix by version rangeDependents
github.com/openbao/openbao—
  • 0.1.0 through 2.5.4: no fix on record
  • every version up to 0.0.0-20260617104123-db57c62602b2: fixed in 0.0.0-20260617104123-db57c62602b2
  • 0.1.0 on: no fix on record
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 9× in last 7d / 38× 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. 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  2. 2026-10-30 10:55 UTCOSV refresh
  3. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  4. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  5. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  6. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  7. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  8. 2026-10-25 14:18 UTCEG score recompute
  9. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  10. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  11. 2026-10-22 21:14 UTCEG score recompute
  12. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  13. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  14. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  15. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  16. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  17. 2026-10-18 03:30 UTCEG score recompute
  18. 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  19. 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  20. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  21. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  22. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  23. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  24. 2026-10-12 15:55 UTCEG score recompute
  25. 2026-10-11 19:38 UTCEG score recompute
Show 31 more
  1. 2026-10-11 16:53 UTCEG score recompute
  2. 2026-10-11 14:16 UTCEG score recompute
  3. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  4. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  5. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  6. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  7. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  8. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  9. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  10. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  11. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  12. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  13. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  14. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  15. 2026-09-29 19:26 UTCEG score recompute
  16. 2026-09-29 15:22 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  17. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  18. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  19. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  20. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  21. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  22. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  23. 2026-09-17 19:31 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  24. 2026-09-17 18:16 UTCEG score recompute
  25. 2026-09-17 15:44 UTCEG score recompute
  26. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  27. 2026-09-15 16:36 UTCEG score recompute
  28. 2026-07-31 04:43 UTCEG score recompute
  29. 2026-07-26 16:46 UTCEG score recompute
  30. 2026-07-23 03:20 UTCEG score recompute
  31. 2026-06-19 22:24 UTCEG score recompute

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Frequently asked(5)

What is CVE-2026-55776?
CVE-2026-55776 is a medium-severity vulnerability; its CVE record was published on June 19, 2026. OpenBao is an open source identity-based secrets management system. Prior to 2.5.5, an authenticated OpenBao caller with write access to transit/keys/* could terminate the server process by setting derived to true while the type parameter selected rsa-, ecdsa-, or ed25519. The Transit policy…
When was the CVE record for CVE-2026-55776 published?
The CVE record for CVE-2026-55776 was published on June 19, 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 September 29, 2026; the record at its source may have been updated since.
Is CVE-2026-55776 actively exploited?
CVE-2026-55776 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.6% probability of exploitation in the next 30 days (49th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-55776?
CVE-2026-55776 has a CVSS base score of 6.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-55776?
A fix for CVE-2026-55776 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-55776 are linked in the Vendor Advisories panel on this page.

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