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CVE-2026-55009

Deserialization of untrusted data in Microsoft Exchange Server allows an authorized attacker to elevate privileges locally.
Lifecycle PUBLISHED1 preserved revisionFact urn:baitaphish:canonical-cve-fact-revision:v2:a7e262c2d3eb9d554df4071704242414ad5e7c60fe555a1c5e9b11f1d9abd751
Known exploited
Not asserted
Disputed
No
Stale source
No
Conflicts
1

Preserved source conflicts

No provider value was silently selected as the winner.

affected · 4 assertions

{"platforms":["x64-based Systems"],"product":"Microsoft Exchange Server Subscription Edition RTM","vendor":"Microsoft","versions":[{"lessThan":"15.02.2562.045","status":"affected","version":"15.02.0.0","versionType":"custom"}]}

  • cve_program_cvelist_v5affected
    urn:baitaphish:normalized-source-record:v2:9bb817de4af3e69448c93aba1860ad098e35e1265102bbe184416ed19214a75d · sha256:4b79d5a05cd78e18… · /containers/cna/affected/3

{"platforms":["x64-based Systems"],"product":"Microsoft Exchange Server 2016 Cumulative Update 23","vendor":"Microsoft","versions":[{"lessThan":"15.01.2507.071","status":"affected","version":"15.01.0.0","versionType":"custom"}]}

  • cve_program_cvelist_v5affected
    urn:baitaphish:normalized-source-record:v2:9bb817de4af3e69448c93aba1860ad098e35e1265102bbe184416ed19214a75d · sha256:4b79d5a05cd78e18… · /containers/cna/affected/0

{"platforms":["x64-based Systems"],"product":"Microsoft Exchange Server 2019 Cumulative Update 15","vendor":"Microsoft","versions":[{"lessThan":"15.02.1748.048","status":"affected","version":"15.02.0.0","versionType":"custom"}]}

  • cve_program_cvelist_v5affected
    urn:baitaphish:normalized-source-record:v2:9bb817de4af3e69448c93aba1860ad098e35e1265102bbe184416ed19214a75d · sha256:4b79d5a05cd78e18… · /containers/cna/affected/2

{"platforms":["x64-based Systems"],"product":"Microsoft Exchange Server 2019 Cumulative Update 14","vendor":"Microsoft","versions":[{"lessThan":"15.02.1544.043","status":"affected","version":"15.02.0.0","versionType":"custom"}]}

  • cve_program_cvelist_v5affected
    urn:baitaphish:normalized-source-record:v2:9bb817de4af3e69448c93aba1860ad098e35e1265102bbe184416ed19214a75d · sha256:4b79d5a05cd78e18… · /containers/cna/affected/1

Affected products and versions

4 source assertions
{"platforms":["x64-based Systems"],"product":"Microsoft Exchange Server Subscription Edition RTM","vendor":"Microsoft","versions":[{"lessThan":"15.02.2562.045","status":"affected","version":"15.02.0.0","versionType":"custom"}]}
  • cve_program_cvelist_v5affected
    urn:baitaphish:normalized-source-record:v2:9bb817de4af3e69448c93aba1860ad098e35e1265102bbe184416ed19214a75d · sha256:4b79d5a05cd78e18… · /containers/cna/affected/3
{"platforms":["x64-based Systems"],"product":"Microsoft Exchange Server 2016 Cumulative Update 23","vendor":"Microsoft","versions":[{"lessThan":"15.01.2507.071","status":"affected","version":"15.01.0.0","versionType":"custom"}]}
  • cve_program_cvelist_v5affected
    urn:baitaphish:normalized-source-record:v2:9bb817de4af3e69448c93aba1860ad098e35e1265102bbe184416ed19214a75d · sha256:4b79d5a05cd78e18… · /containers/cna/affected/0
{"platforms":["x64-based Systems"],"product":"Microsoft Exchange Server 2019 Cumulative Update 15","vendor":"Microsoft","versions":[{"lessThan":"15.02.1748.048","status":"affected","version":"15.02.0.0","versionType":"custom"}]}
  • cve_program_cvelist_v5affected
    urn:baitaphish:normalized-source-record:v2:9bb817de4af3e69448c93aba1860ad098e35e1265102bbe184416ed19214a75d · sha256:4b79d5a05cd78e18… · /containers/cna/affected/2
{"platforms":["x64-based Systems"],"product":"Microsoft Exchange Server 2019 Cumulative Update 14","vendor":"Microsoft","versions":[{"lessThan":"15.02.1544.043","status":"affected","version":"15.02.0.0","versionType":"custom"}]}
  • cve_program_cvelist_v5affected
    urn:baitaphish:normalized-source-record:v2:9bb817de4af3e69448c93aba1860ad098e35e1265102bbe184416ed19214a75d · sha256:4b79d5a05cd78e18… · /containers/cna/affected/1

Provider-owned CVSS observations

1 source assertion
{"metric":{"baseScore":7.8,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C","version":"3.1"},"metric_type":"cvssV3_1"}
  • cve_program_cvelist_v5cvss
    urn:baitaphish:normalized-source-record:v2:9bb817de4af3e69448c93aba1860ad098e35e1265102bbe184416ed19214a75d · sha256:4b79d5a05cd78e18… · /containers/cna/metrics/0/cvssV3_1

CWE assertions

1 source assertion
{"cweId":"CWE-502","description":"CWE-502: Deserialization of Untrusted Data","lang":"en-US","type":"CWE"}
  • cve_program_cvelist_v5cwe
    urn:baitaphish:normalized-source-record:v2:9bb817de4af3e69448c93aba1860ad098e35e1265102bbe184416ed19214a75d · sha256:4b79d5a05cd78e18… · /containers/cna/problemTypes/0/descriptions/0

Source references

1 source assertion
{"name":"Microsoft Exchange Server Elevation of Privilege Vulnerability","tags":["vendor-advisory","patch"],"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55009"}
  • cve_program_cvelist_v5reference
    urn:baitaphish:normalized-source-record:v2:9bb817de4af3e69448c93aba1860ad098e35e1265102bbe184416ed19214a75d · sha256:4b79d5a05cd78e18… · /containers/cna/references/0

Attribution and limitations

  • CVE Program CVEList V5: Reproduce the MITRE copyright designation and CVE license in copies. Source →

Provider severity values are preserved separately. Baitaphish does not convert them into a risk rating, infer affected products, or treat EPSS as observed exploitation.

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