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TI-2026-31952 Aliases CVE-2026-43888

Outline: Zip Extraction Path Escape via PATH_MAX Truncation in Collection Import

Priority HIGH 73CWE-22Published · Updated

Key facts

Attack vector
Network
Privileges required
High
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
None · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA.

Summary

Outline is a service that allows for collaborative documentation. Prior to 1.7.0, ZipHelper.extract computes the extraction path for each entry by passing a full filesystem path through trimFileAndExt, a filename helper that calls path.basename on its input when truncating. When a zip entry's nested path is long enough to push the joined filesystem path over MAX_PATH_LENGTH (4096 bytes), trimFileAndExt silently drops all directory components and returns a bare filename. fs.createWriteStream then opens the file relative to the process working directory instead of inside the extraction sandbox, and the escaped file persists after import cleanup because cleanupExtractedData only removes the temporary extraction directory. This vulnerability is fixed in 1.7.0.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00368 30th percentileScored 2026-11-07
Fix Fixed outline (outline): 1.7.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
outlineoutlinebefore 1.7.01.7.0Patch availableCNA
  • outline Vendoroutline Affected before 1.7.0 Fixed in 1.7.0 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:getoutline:outline:*:*:*:*:*:*:*:*——outline
  • cpe:2.3:a:getoutline:outline:*:*:*:*:*:*:*:* Versions — — ·outline

Remediation

  • Fix · CNA outline (outline) Fixed in 1.7.0

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-43888

References

Other 1

  • TI-2026-26021 Outline has a rate limit bypass that allows brute force of email login OTP CVSS 4.0CRITICAL 9.1
  • TI-2026-20086 Outline's IDOR allows unauthorized viewing and seizing of private deleted drafts CVSS 3.1HIGH 8.8
  • TI-2024-25167 An issue in Outline <= v0.76.1 allows attackers to execute a session hijacking attack via… CVSS 3.1HIGH 8.8
  • TI-2020-19165 Outline Service 1.3.3 - 'Outline Service ' Unquoted Service Path CVSS 4.0HIGH 8.5
  • TI-2026-83841 Outline exposes unpublished documents through public share links CVSS 4.0MEDIUM 6.9
  • TI-2026-31950 Outline: OAuth Scope Validation Logic Error Allows Privilege Escalation to Wildcard API Access CVSS 3.1HIGH 8.2
See all 24 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences