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CVE-2026-103239

HIGH 8.6

Published 2026-09-30 · Last modified 2026-09-30

MISP contains a privilege escalation vulnerability in the tag collection creation and editing functionality. The affected actions accepted the full HTTP request payload and passed it to a bulk-association save operation, which writes not only the intended tag collection record but also any associated model data present in the payload. A user holding the tag editor permission could craft a request that includes additional model data (such as User or Organisation records) alongside the tag collection fields. Because the save operation processed all associated models indiscriminately, the injected sibling records were written to the database, enabling the attacker to modify or create privileged accounts and escalate to site administrator. Preconditions: - An authenticated account with the tag editor permission (perm_tag_editor) - Network access to the MISP instance Impact: - Unauthorized creation or modification of User and Organisation records - Privilege escalation from tag editor to site administrator Affected versions: < 2.5.48

ELEVATED IMPACT

Severe if exploited (CVSS 8.6), but no known exploitation and low modeled probability. Patch on a normal cadence.

Exploitation likelihood

0.3%chance of exploitation in 30 days · 16th percentile

○ In CISA KEV ○ Public exploit / PoC

Impact if exploited

8.6CVSS 4.0 · HIGH

  • ConfidentialityHigh
  • IntegrityHigh
  • AvailabilityNone

What an attacker needs

  • ✓Access: Reachable over the network — no local access needed
  • ⚠Privileges: Requires a low-privilege account
  • ✓User interaction: No user interaction needed
  • ✓Complexity: No special conditions — reliably repeatable
  • ✓Requirements: No special attack requirements

✓ lowers the bar for an attacker · ⚠ raises it

Proof of concept & exploit code

Test against your own equipment

curl -s https://vulnpedia.com/cve/CVE-2026-103239/poc.jsonMachine-readable PoC index for this CVE (for automation).

Listed for defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-103239/poc.json

Affected

Vendors Misp

Products Misp

Weakness (CWE)

  • CWE-284: Improper Access Control
  • CWE-862: Missing Authorization

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

All CVSS metrics

  • HIGH 8.6 v4.0 · CNA Primary
    CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
  • HIGH 8.6 v4.0 · NVD Secondary
    CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

References

Sources: NVD · CVE.org · EPSS