CVE-2026-91132

MEDIUMPre-NVD 4.34.3
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to the CVSS score beside it.

This medium-severity CVE scores 4.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.1% (3rd percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from a secondary CVSS source
Sources: EPSS, a secondary CVSS source

Also known asEUVD-2026-86303 (ENISA EUVD)Source: ENISA EUVD

4.3EG
EchelonGraph verdictMonitorRemediate within your standard update timelines (the SSVC decision on this page).
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.1%CVSS: 4.3Exploit: None knownExposed services: Not assessed

The CVE record names the fixed release — apply it.

Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, sites using wildcard patterns in the allowed_iframes setting could accept a crafted iframe URL whose allowlisted suffix appeared after a URL authority separator. The wildcard origin check matched the allowed domain text, while browser URL parsing selected a different attacker-controlled origin. A user with posting privileges could exploit the flaw through a post or a Onebox oEmbed response and cause an attacker-controlled iframe to be rendered independently of the allowlisted domain. Successful exploitation requires a site-configured wildcard iframe pattern and the ability to create a post or trigger an oEmbed request for an attacker-controlled URL. This issue is fixed in versions 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0.

CVSS v3
4.3
EG Score
4.3MEDIUMmedium confidence
EG Risk
19
EG Risk 19/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity43% × 45%
Impact severity (EG Severity): CVSS 4.3 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.1% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at every mission impact level.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: The CVE record names the fixed release. Apply it within your standard update timelines.
EPSS PROB
0.1%
EPSS %ILE
3rd
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (4.3): severity, escalated by confirmed exploitation. This CVE's 4.3 is its impact severity (EG Severity), not escalated.

EG Severity
4.3 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.a secondary CVSS source · CVSS v3.0 or v3.1
EG Likelihood
0.1% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-24). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.

The CVE record names the fixed release. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

September 24, 2026

Last Modified

September 29, 2026

Advisory Details (6)

Auto-updated Sep 24, 2026
Fix named in the CVE record. Sources: github, github_pr, github_commit.
GitHub commit

commit db8064f2a2a2 (discourse/discourse)

Fix landed in discourse/discourse commit db8064f2a2a2 — awaiting tagged release

https://github.com/discourse/discourse/commit/db8064f2a2a2a3feb3308a1c932ac61d950c9e56
GitHub commit

commit d88e02ceb2ee (discourse/discourse)

Fix landed in discourse/discourse commit d88e02ceb2ee — awaiting tagged release

https://github.com/discourse/discourse/commit/d88e02ceb2eede4d8b851d9fe8aef753f3aa40b9
GitHub commit

commit d5ae0940707f (discourse/discourse)

Fix landed in discourse/discourse commit d5ae0940707f — awaiting tagged release

https://github.com/discourse/discourse/commit/d5ae0940707f95da5bc4562f7b544243e3103f8a
GitHub commit

commit 80968704c1ac (discourse/discourse)

Fix landed in discourse/discourse commit 80968704c1ac — awaiting tagged release

https://github.com/discourse/discourse/commit/80968704c1acb1d2ea2c6011dbf6c02ff13238e5
GitHub pull request

Security fixes for main

Fix merged in discourse/discourse PR #42882 on 2026-08-25 — awaiting tagged release

https://github.com/discourse/discourse/pull/42882
GitHub advisoryMentions a patch (unverified)

Wildcard iframe origin allowlist bypass via authority separators · Advisory · discourse/discourse · GitHub

https://github.com/discourse/discourse/security/advisories/GHSA-4q3q-hph3-3rvp

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 8× in last 7d / 45× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 1 repeat row among the latest 62 is merged into the row it repeats.

  1. 2026-11-01 16:36 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  2. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  3. 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  4. 2026-10-29 22:25 UTCOSV refresh
  5. 2026-10-29 16:34 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  6. 2026-10-28 16:33 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  7. 2026-10-27 16:33 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  8. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  9. 2026-10-25 16:34 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  10. 2026-10-25 13:51 UTCEG score recompute
  11. 2026-10-24 16:34 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  12. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  13. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  14. 2026-10-22 12:30 UTCEG score recompute
  15. 2026-10-21 16:34 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  16. 2026-10-20 16:34 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  17. 2026-10-19 16:33 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  18. 2026-10-18 16:33 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  19. 2026-10-18 03:00 UTCEG score recompute
  20. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  21. 2026-10-16 16:45 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  22. 2026-10-15 16:33 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  23. 2026-10-14 16:34 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  24. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  25. 2026-10-12 16:35 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
Show 36 more
  1. 2026-10-12 14:46 UTCEG score recompute
  2. 2026-10-11 19:13 UTCEG score recompute
  3. 2026-10-11 16:30 UTCEG score recompute
  4. 2026-10-11 13:50 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  5. 2026-10-11 13:44 UTCEG score recompute
  6. 2026-10-11 06:23 UTCEG score recompute
  7. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  8. 2026-10-10 06:07 UTCEG score recompute
  9. 2026-10-09 20:08 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  10. 2026-10-09 05:54 UTCEG score recompute
  11. 2026-10-08 17:14 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  12. 2026-10-08 05:41 UTCEG score recompute
  13. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  14. 2026-10-07 05:27 UTCEG score recompute
  15. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  16. 2026-10-06 05:14 UTCEG score recompute
  17. 2026-10-05 17:44 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  18. 2026-10-05 04:56 UTCEG score recompute
  19. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  20. 2026-10-04 04:43 UTCEG score recompute
  21. 2026-10-03 04:30 UTCEG score recompute
  22. 2026-10-02 04:17 UTCEG score recompute
  23. 2026-10-01 19:51 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  24. 2026-10-01 03:56 UTCEG score recompute
  25. 2026-09-30 15:04 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  26. 2026-09-29 03:30 UTCEG score recompute
  27. 2026-09-29 03:02 UTCEG score recompute
  28. 2026-09-28 18:55 UTCEG score recompute
  29. 2026-09-28 13:52 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  30. 2026-09-27 18:42 UTCEG score recompute
  31. 2026-09-27 13:49 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  32. 2026-09-26 18:29 UTCEG score recompute
  33. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  34. 2026-09-24 17:33 UTCEG score recompute
  35. 2026-09-24 17:02 UTCEG score recomputeFirst assessed: 4.3 MEDIUM
  36. 2026-09-24 17:01 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-91132?
CVE-2026-91132 is a medium-severity vulnerability; its CVE record was published on September 24, 2026. Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, sites using wildcard patterns in the allowed_iframes setting could accept a crafted iframe URL whose allowlisted suffix appeared after a URL authority separator. The wildcard origin check matched…
When was the CVE record for CVE-2026-91132 published?
The CVE record for CVE-2026-91132 was published on September 24, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of September 29, 2026; the record at its source may have been updated since.
Is CVE-2026-91132 actively exploited?
CVE-2026-91132 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.1% probability of exploitation in the next 30 days (3rd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-91132?
CVE-2026-91132 has a CVSS base score of 4.3 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-91132?
The CVE record for CVE-2026-91132 names the fix: "This issue is fixed in versions 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0."

Dependency Blast Radius

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