CASCACascade Atlas

Evidence dossier

CVE-2021-26085

Affected versions of Atlassian Confluence Server allow remote attackers to view restricted resources via a Pre-Authorization Arbitrary File Read vulnerability in the /s/ endpoint.

Exploited in the wild (CISA KEV since Mar 28, 2022). NVD reports CVSS 3.1 5.3. EPSS estimates 99.9% exploit likelihood as of Jul 26, 2026.

76.8–79.0Priority evidence range
Evidence current through Aug 27, 2026, 6:09 PM UTC

As of Aug 27, 2026

Normalized restatement

Affected versions of Atlassian Confluence Server allow remote attackers to view restricted resources via a Pre-Authorization Arbitrary File Read vulnerability in the /s/ endpoint. The affected versions are before version 7.4.10, and from version 7.5.0 before 7.12.3.

State
PUBLISHED
Published
Aug 3, 2021
Updated
Oct 21, 2025
Evidence coverage
95%

Evidence chronology

What was known when

Download this view's receipt →
  1. Source dateSource date omittedFirst observed by CASCA
    atlassian

    Record text: Affected versions of Atlassian Confluence Server allow remote attackers to view restricted resources via a Pre-Authorization Arbitrary File Read vulnerability in the /s/ endpoint. The affected versions are before version 7.4.10, and from version 7.5.0 before 7.12.3.

    Inspect raw assertion
    Field
    container
    Value
    Affected versions of Atlassian Confluence Server allow remote attackers to view restricted resources via a Pre-Authorization Arbitrary File Read vulnerability in the /s/ endpoint. The affected versions are before version 7.4.10, and from version 7.5.0 before 7.12.3.
    Original evidence ↗
  2. Source dateSource date omittedFirst observed by CASCA
    CISA-ADP

    Record text: CISA ADP Vulnrichment

    Inspect raw assertion
    Field
    container
    Value
    CISA ADP Vulnrichment
    Original evidence ↗
  3. Source dateSource date omittedFirst observed by CASCA
    CVE Program

    Record text: CVE Program Container

    Inspect raw assertion
    Field
    container
    Value
    CVE Program Container
    Original evidence ↗
  4. Source dateFirst observed by CASCA
    CISA KEV

    Exploitation cataloged: Atlassian Confluence Server Pre-Authorization Arbitrary File Read Vulnerability

    Inspect raw assertion
    Field
    observed_exploitation
    Value
    Atlassian Confluence Server Pre-Authorization Arbitrary File Read Vulnerability
    Original evidence ↗
  5. Source dateFirst observed by CASCA
    FIRST EPSS

    EPSS score: 99.94% probability · 99.97th percentile

    Inspect raw assertion
    Field
    model_probability
    Value
    Probability 0.999370000000; percentile 0.999700000000
    Original evidence ↗
ExploitationCatalog member

CISA KEV · catalog date Mar 28, 2022 · first observed Jul 19, 2026

Exploit likelihood99.94%

FIRST EPSS · score date Jul 26, 2026 · 100th percentile · first observed Jul 27, 2026

SeverityCVSS 5.3

NVD · CVSS 3.1 · first observed Jul 19, 2026 · same-version scores align in this snapshot

Evidence detail

Source limits and decisions

Why each evidence state has this value

casca-unknown-reasons-v1
Exploitation statusEvidence supported

Eligible evidence is present for this bounded claim.

Revision
evidence-policy-v1.1.0
Cutoff
Aug 27, 2026
Resolution
None
Exploit likelihoodEvidence supported

Eligible evidence is present for this bounded claim.

Revision
evidence-policy-v1.1.0
Cutoff
Aug 27, 2026
Resolution
None
Severity assessmentEvidence supported

Eligible evidence is present for this bounded claim.

Revision
casca-direct-cvss-eligibility-v1
Cutoff
Aug 27, 2026
Resolution
None
Affected productsSource-reported scope

The cited source assertion is retained while canonical product linkage remains open.

Revision
casca-factor-d-obligations-v1
Cutoff
Aug 27, 2026
Resolution
Resolve identity

Source comparison

Who said what

atlassianOriginal assertion
Record text

Affected versions of Atlassian Confluence Server allow remote attackers to view restricted resources via a Pre-Authorization Arbitrary File Read vulnerability in the /s/ endpoint. The affected versions are before version 7.4.10, and from version 7.5.0 before 7.12.3.

Inspect raw assertion
Field
container
Value
Affected versions of Atlassian Confluence Server allow remote attackers to view restricted resources via a Pre-Authorization Arbitrary File Read vulnerability in the /s/ endpoint. The affected versions are before version 7.4.10, and from version 7.5.0 before 7.12.3.
Source dateSource date omittedFirst observed by CASCAOriginal evidence ↗
CISA-ADPIndependent enrichment
Record text

CISA ADP Vulnrichment

Inspect raw assertion
Field
container
Value
CISA ADP Vulnrichment
Source dateSource date omittedFirst observed by CASCAOriginal evidence ↗
CVE ProgramDerivative copy
Record text

CVE Program Container

Inspect raw assertion
Field
container
Value
CVE Program Container
Source dateSource date omittedFirst observed by CASCAOriginal evidence ↗
CISA KEVOriginal assertion
Exploitation cataloged

Atlassian Confluence Server Pre-Authorization Arbitrary File Read Vulnerability

Inspect raw assertion
Field
observed_exploitation
Value
Atlassian Confluence Server Pre-Authorization Arbitrary File Read Vulnerability
Source dateFirst observed by CASCAOriginal evidence ↗
FIRST EPSSOriginal assertion
EPSS score

99.94% probability · 99.97th percentile

Inspect raw assertion
Field
model_probability
Value
Probability 0.999370000000; percentile 0.999700000000
Source dateFirst observed by CASCAOriginal evidence ↗

Applicability

Cited product scope

Trace impact →
4Underlying assertions
2Canonical products
4Target assertions
0Constraint assertions

Grouped from 1 configuration nodes in this exact snapshot. Visual grouping is navigational; asset exposure and root cause require cited evidence.

Identity source boundaries
  • Cpe dictionary1,775,266 records · observed through 2026-07-21T06:45:29.809Z27d65b0f-b718-4b4f-bb79-c47c68d09dfa
  • Cpe match643,502 records · observed through 2026-07-21T08:13:17.697Z955dae73-7302-438b-aee1-058d7cc5d48e

4 scope groups

atlassian · source assertedAtlassianConfluence Data CenterDirect source scope
Affected: unspecified to before 7.4.10 (custom comparison)Affected: 7.5.0 to before unspecified (custom comparison)Affected: unspecified to before 7.12.3 (custom comparison)
Source-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Inspect raw assertion[{"status": "affected", "version": "unspecified", "lessThan": "7.4.10", "versionType": "custom"}, {"status": "affected", "version": "7.5.0", "lessThan": "unspecified", "versionType": "custom"}, {"status": "affected", "version": "unspecified", "lessThan": "7.12.3", "versionType": "custom"}]
atlassian · source assertedAtlassianConfluence ServerDirect source scope
Affected: unspecified to before 7.4.10 (custom comparison)Affected: 7.5.0 to before unspecified (custom comparison)Affected: unspecified to before 7.12.3 (custom comparison)
Source-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Inspect raw assertion[{"status": "affected", "version": "unspecified", "lessThan": "7.4.10", "versionType": "custom"}, {"status": "affected", "version": "7.5.0", "lessThan": "unspecified", "versionType": "custom"}, {"status": "affected", "version": "unspecified", "lessThan": "7.12.3", "versionType": "custom"}]
NVD CPE · APPLICATIONatlassianconfluence_data_centerVulnerable target · 2 assertions
Any version (unconstrained) (< 7.4.10); Any version (unconstrained) (>= 7.5.0, < 7.12.3)Canonical identity product-46ffcc1c487e05351f85b32368995272472629a66f00f7c366711e9ad6b50a1eLinked exact
Scope supported
Inspect raw assertions
  1. cpe:2.3:a:atlassian:confluence_data_center:*:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 0
    Logic
    OR
    Version bounds
    through excluding 7.4.10
    Match ID
    83557716-7a48-48d5-85a9-4a29dbf4f511
  2. cpe:2.3:a:atlassian:confluence_data_center:*:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 1
    Logic
    OR
    Version bounds
    from including 7.5.0; through excluding 7.12.3
    Match ID
    6a310d77-1fff-4ffe-ad50-75dff973eb3f
NVD CPE · APPLICATIONatlassianconfluence_serverVulnerable target · 2 assertions
Any version (unconstrained) (< 7.4.10); Any version (unconstrained) (>= 7.5.0, < 7.12.3)Canonical identity product-d78d3c5ab9c4bc766839e98def83496ad4b2f4f37b30094660d7525704ae86c2Linked exact
Scope supported
Inspect raw assertions
  1. cpe:2.3:a:atlassian:confluence_server:*:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 3
    Logic
    OR
    Version bounds
    from including 7.5.0; through excluding 7.12.3
    Match ID
    b1148df0-42c0-435f-a6eb-efa93e10e8d7
  2. cpe:2.3:a:atlassian:confluence_server:*:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 2
    Logic
    OR
    Version bounds
    through excluding 7.4.10
    Match ID
    4ba04112-3b97-491b-93e6-80c444274430

Affected-product evidence

Accepted scope and product mapping

2 canonical links · 1 source-reported links

Mapping establishedEvidence supported

vendor-2c6716ad07a7f126f6c3b10254124705a45f0fa6586f2803bb482afd1584ee5f · product-46ffcc1c487e05351f85b32368995272472629a66f00f7c366711e9ad6b50a1e

Source class
Nvd cpe vulnerable target
Assertions
2
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
5fae3f82-7eb6-47f7-aedb-9b81e3fae7e9d1b844f0-3ee9-43f8-b6c2-1a3ab85b0e63
Mapping establishedEvidence supported

vendor-2c6716ad07a7f126f6c3b10254124705a45f0fa6586f2803bb482afd1584ee5f · product-d78d3c5ab9c4bc766839e98def83496ad4b2f4f37b30094660d7525704ae86c2

Source class
Nvd cpe vulnerable target
Assertions
2
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
37dc505d-f6da-437f-ad24-372d10d82ac36a78a343-ecec-49c8-9f98-ba0845a980a7
Source-reported scopeSource-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Vendor specified only by source · Product specified only by source

Source class
Direct cve affected
Assertions
2
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
1ac47ef1-6c2f-49e9-9896-3572d8c813c846a36ec2-beb0-4ca0-8328-988d06e47ea5

Assessments

CVSS by origin

5.3
NVDCVSS 3.1 · role Primary · priority eligiblevalid_matchCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
5.0
NVDCVSS 2.0 · role Primary · priority eligiblevalid_matchAV:N/AC:L/Au:N/C:P/I:N/A:N
5.3
CVE Program sourceCVSS 3.1 · role Secondary · priority eligiblevalid_matchCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
5.3
CISA-ADPCVSS 3.1 · role unknown · display onlyDirect record assessment retained outside normalized eligibilityCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Direct CVE/CNA normalized decisions

5.3Priority eligible

CISA-ADP

CVSS 3.1 · Secondary · Independent enrichment · rank 2

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Validation
Valid match
Recomputed
5.3
Decision reason
Evidence supported
Policy
casca-direct-cvss-eligibility-v1

Assessments are retained side by side under closed precedence. Cascade never averages CVSS.

Evidence boundaries

  • KEV membership is authoritative for the catalog, not proof of exposure in any environment.
  • EPSS is a dated model probability and not an individual-environment prediction.
  • Affected or fixed status applies only to the exact cited product and version scope; remaining scope stays source-scoped.
  • NVD-carried upstream facts remain derivative; independent corroboration requires a separately authored source.
  • Only NVD metrics validated under the generation-bound calculator are Public Priority eligible; direct CVE record metrics remain display-only.
  • NVD CVSS source eligibility is closed: NVD-authored, exact record-source, or registered same-CVE container origin; unmapped sources remain display-only.
  • Core replay supports the active and immediately prior generation; retrospective valid-at replay is deferred.
  • OSV aggregation and OSV-converted NVD material are not independent corroboration.
  • Red Hat facts are vendor assertions for the exact supplied products.
  • Nonmembership and not-yet-observed states are not proof of safety.