CVE-2026-73496

HIGHPre-NVD 7.77.7
EchelonGraph scoreMEDIUM confidence

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

This high-severity CVE scores 7.7 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.5% (41st 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
Elevated

Also known asEUVD-2026-77795 (ENISA EUVD)Source: ENISA EUVD

7.7EG
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: 0.5%CVSS: 7.7Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, the confluence_upload_attachment and confluence_upload_attachments tools pass a client-controlled file_path through src/mcp_atlassian/confluence/attachments.py upload_attachment, and the jira_update_issue attachments parameter reaches src/mcp_atlassian/jira/attachments.py upload_attachment, without confining either path to an approved server workspace. In a remote HTTP, SSE, or multi-user deployment, absolute or traversing paths are resolved on the MCP server and uploaded to Atlassian, allowing a client with write-tool access to disclose server files, environment-held Atlassian credentials, or another tenant's data. A local single-user stdio deployment does not cross this trust boundary because the server runs in the caller's environment. This issue is fixed in version 0.22.0.

CVSS v3
7.7
EG Score
7.7HIGHmedium confidence
EG Risk
51
EG Risk 51/100

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)
Severity77% × 45%
Impact severity (EG Severity): CVSS 7.7 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
0.5%
EPSS %ILE
41st
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 (7.7): severity, escalated by confirmed exploitation. This CVE's 7.7 is its impact severity (EG Severity), not escalated.

EG Severity
7.7 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
0.5% 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 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, 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; 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.

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

September 14, 2026

Last Modified

September 30, 2026

Advisory Details (4)

Auto-updated Sep 14, 2026
Patch available. Sources: github, github_pr, github_commit, github_release.
GitHub release Patch Available

v0.22.0

Patch available: sooperset/mcp-atlassian v0.22.0

https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0
GitHub commit Patch Available

commit b041733473f9 (sooperset/mcp-atlassian)

Patch available: sooperset/mcp-atlassian v0.22.0 (contains commit b041733473f9)

https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460
GitHub pull request Patch Available

Security hardening across attachment, transport, SSRF, authorization, filter, and OAuth layers

Patch available: sooperset/mcp-atlassian v0.22.0 (PR #1448 merged 2026-07-10)

https://github.com/sooperset/mcp-atlassian/pull/1448
GitHub advisoryMentions a patch (unverified)

Arbitrary server-side file read via attachment upload in mcp-atlassian · Advisory · sooperset/mcp-atlassian · GitHub

https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-wm45-qh3g-v83f

Affected Packages

(1 across 1 ecosystem)
PyPI(1)
PackageVulnerable rangeFix by version rangeDependents
mcp-atlassian0.1.1 ... 0.9.0 (79 versions)
  • every version up to 0.22.0: fixed in 0.22.0
—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 8× in last 7d / 47× 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 0.5% · 41st percentile
  2. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  3. 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  4. 2026-10-29 16:34 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  5. 2026-10-28 16:33 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  6. 2026-10-27 19:04 UTCEG score recompute
  7. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  8. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  9. 2026-10-25 16:34 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  10. 2026-10-25 14:05 UTCEG score recompute
  11. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  12. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  13. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  14. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  15. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  16. 2026-10-20 08:29 UTCEG score recompute
  17. 2026-10-19 16:33 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  18. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  19. 2026-10-18 03:15 UTCEG score recompute
  20. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  21. 2026-10-16 16:44 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  22. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  23. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  24. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  25. 2026-10-13 07:53 UTCEG score recompute
Show 55 more
  1. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  2. 2026-10-12 15:40 UTCEG score recompute
  3. 2026-10-11 19:26 UTCEG score recompute
  4. 2026-10-11 16:42 UTCEG score recompute
  5. 2026-10-11 14:01 UTCEG score recompute
  6. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  7. 2026-10-11 06:02 UTCEG score recompute
  8. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  9. 2026-10-10 03:06 UTCEG score recompute
  10. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  11. 2026-10-08 23:25 UTCEG score recompute
  12. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  13. 2026-10-08 01:28 UTCEG score recompute
  14. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  15. 2026-10-06 16:08 UTCEG score recompute
  16. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  17. 2026-10-05 18:24 UTCEG score recompute
  18. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  19. 2026-10-05 07:33 UTCEG score recompute
  20. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  21. 2026-10-03 22:53 UTCEG score recompute
  22. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  23. 2026-10-03 01:09 UTCEG score recompute
  24. 2026-10-02 03:22 UTCEG score recompute
  25. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  26. 2026-09-30 18:09 UTCEG score recompute
  27. 2026-09-30 01:27 UTCEG score recompute
  28. 2026-09-29 15:24 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  29. 2026-09-28 23:52 UTCEG score recompute
  30. 2026-09-28 13:52 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  31. 2026-09-27 15:14 UTCEG score recompute
  32. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  33. 2026-09-26 17:27 UTCEG score recompute
  34. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  35. 2026-09-26 06:35 UTCEG score recompute
  36. 2026-09-24 21:41 UTCEG score recompute
  37. 2026-09-23 23:32 UTCEG score recompute
  38. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  39. 2026-09-23 01:50 UTCEG score recompute
  40. 2026-09-22 04:08 UTCEG score recompute
  41. 2026-09-21 21:09 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  42. 2026-09-21 06:25 UTCEG score recompute
  43. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  44. 2026-09-19 21:52 UTCEG score recompute
  45. 2026-09-19 00:09 UTCEG score recompute
  46. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  47. 2026-09-18 02:26 UTCEG score recompute
  48. 2026-09-16 17:51 UTCEG score recompute
  49. 2026-09-16 16:55 UTCEG score recompute
  50. 2026-09-16 15:57 UTCEG score recompute
  51. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  52. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  53. 2026-09-14 20:21 UTCEG score recompute
  54. 2026-09-14 19:55 UTCEG score recomputeFirst assessed: 7.7 HIGH
  55. 2026-09-14 19:54 UTCMITRE cvelistV5first tracked

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Frequently asked(5)

What is CVE-2026-73496?
CVE-2026-73496 is a high-severity vulnerability; its CVE record was published on September 14, 2026. MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, the confluence_upload_attachment and confluence_upload_attachments tools pass a client-controlled file_path through src/mcp_atlassian/confluence/attachments.py upload_attachment,…
When was the CVE record for CVE-2026-73496 published?
The CVE record for CVE-2026-73496 was published on September 14, 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 30, 2026; the record at its source may have been updated since.
Is CVE-2026-73496 actively exploited?
CVE-2026-73496 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (41st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-73496?
CVE-2026-73496 has a CVSS base score of 7.7 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-73496?
A fix for CVE-2026-73496 is available: update to the fixed version the vendor names in its advisory.

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