CVE-2026-81820

MEDIUMPre-NVD 5.15.1—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.1 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 84% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Trending — 4 sources updated this week
5.1EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.1Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Affected versions of Flowintel construct timeline HTML using attacker-controllable MISP object fields such as:

* object UUID;

* object name;

* attribute value;

* attribute type;

* comment;

* first/last seen values;

* IDS flag.

Those values were concatenated directly into HTML strings before rendering. The upstream commit explicitly states that DOMPurify removed XSS vectors but still allowed other HTML elements, such as forms, through.

The fix replaces direct string interpolation with DOM construction via document.createElement() and assigns all attacker-controlled values using textContent. The headline is similarly converted to escaped HTML through a temporary element.

Version impacted =>3.3.0

CVSS v3
5.1
EG Score
5.1(medium)
EG Risk
28(Track)
EG Risk 28/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity51% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
16%
KEV
Not listed

Published

August 27, 2026

Last Modified

August 28, 2026

Advisory Details (1)

Auto-updated Aug 27, 2026
No patch confirmed yet.
generic
https://github.com/flowintel/flowintel/commit/11f71e747d95ed062667e2df0ce259c5fa64d531.patch

Vendor Advisories for CVE-2026-81820(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 9× in last 7d / 9× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. 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. Most recent first.

  1. 2026-08-30 01:22 UTCEPSS rescore
  2. 2026-08-29 16:08 UTCEG score recompute
  3. 2026-08-29 16:08 UTCGHSA enrichment
  4. 2026-08-28 21:42 UTCEPSS rescore
  5. 2026-08-28 15:43 UTCGHSA enrichment
  6. 2026-08-27 20:28 UTCGHSA enrichment
  7. 2026-08-27 17:27 UTCEG score recompute
  8. 2026-08-27 16:49 UTCEG score recompute
  9. 2026-08-27 16:43 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-81820?
CVE-2026-81820 is a medium vulnerability published on August 27, 2026. Affected versions of Flowintel construct timeline HTML using attacker-controllable MISP object fields such as: object UUID; object name; attribute value; attribute type; comment; first/last seen values; IDS flag. Those values were concatenated directly into HTML strings before rendering. The…
When was CVE-2026-81820 disclosed?
CVE-2026-81820 was first published in the National Vulnerability Database on August 27, 2026, with the most recent update on August 28, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-81820 actively exploited?
CVE-2026-81820 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 83.6% of all scored CVEs.
What is the CVSS score of CVE-2026-81820?
CVE-2026-81820 has a CVSS v3 base score of 5.1 (NVD).
How do I remediate CVE-2026-81820?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-81820, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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