CVE-2026-81887

MEDIUMPre-NVD 5.15.1
EchelonGraph scoreMEDIUM confidence

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

This medium-severity CVE scores 5.1 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.7% (53rd 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-2026-68765 (ENISA EUVD) · GHSA-g3hc-697w-wm82 (GitHub Security Advisories)Source: ENISA EUVD

5.1EG
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: 0.7%CVSS: 5.1Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Livewire is a full-stack framework for Laravel. From 3.0.0-beta.1 until 3.8.3 and 4.3.4, the dot-notated query-string parser in js/plugins/history/index.js, including fromQueryString() and insertDotNotatedValueIntoData(), accepts the __proto__, constructor, and prototype path segments and creates inherited objects. Client-side state handlers then access effects.html, effects.js, effects.xjs, and effects.scripts without Object.prototype.hasOwnProperty.call(), allowing inherited attacker-controlled state to be treated as trusted effects. An unauthenticated attacker can craft a URL that, when opened by a user, executes arbitrary JavaScript in the affected application's origin. Exploitation requires user interaction and does not bypass server-side authorization or grant privileges beyond the affected user. This issue is fixed in versions 3.8.3 and 4.3.4.

CVSS
5.1
EG Score
5.1MEDIUMmedium confidence
EG Risk
23
EG Risk 23/100

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)
Severity51% × 45%
Impact severity (EG Severity): CVSS 5.1 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.7% × 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: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.7%
EPSS %ILE
53rd
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 (5.1): severity, escalated by confirmed exploitation. This CVE's 5.1 is its impact severity (EG Severity), not escalated.

EG Severity
5.1 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.a secondary CVSS source
EG Likelihood
0.7% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-31). 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.

A fix is available. 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

August 31, 2026

Last Modified

September 9, 2026

Advisory Details (5)

Auto-updated Aug 31, 2026
Patch available. Sources: github, github_pr, github_commit, github_release.
GitHub release Patch Available

v4.3.4

Patch available: livewire/livewire v4.3.4

https://github.com/livewire/livewire/releases/tag/v4.3.4
GitHub release Patch Available

v3.8.3

Patch available: livewire/livewire v3.8.3

https://github.com/livewire/livewire/releases/tag/v3.8.3
GitHub commit Patch Available

commit 11ebe646f7e8 (livewire/livewire)

Patch available: livewire/livewire v3.8.3 (contains commit 11ebe646f7e8)

https://github.com/livewire/livewire/commit/11ebe646f7e81dde2d714815da8b3019d058561e
GitHub pull request Patch Available

[3.x] Improve query string parsing and effect handling

Patch available: livewire/livewire v3.8.3 (PR #10467 merged 2026-07-30)

https://github.com/livewire/livewire/pull/10467
GitHub advisoryMentions a patch (unverified)

Livewire DOM-based cross-site scripting during client-side state handling · Advisory · livewire/livewire · GitHub

https://github.com/livewire/livewire/security/advisories/GHSA-g3hc-697w-wm82

Vendor Advisories for CVE-2026-81887(1)

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

Patch Availability(2)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
composerlivewire/livewire @ 3.8.3 (fixes >= 3.0.0-beta.1, <= 3.8.2)—ghsa
composerlivewire/livewire @ 4.3.4 (fixes >= 4.0.0-beta.1, <= 4.3.3)—ghsa

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(1 across 1 ecosystem)
Packagist(1)
PackageVulnerable rangeFix by version rangeDependents
livewire/livewirev4.0.0 ... v4.3.3 (25 versions)
  • 3.0.0-beta.1 up to 3.8.3: fixed in 3.8.3
  • 4.0.0-beta.1 up to 4.3.4: fixed in 4.3.4
—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 32× 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 its CVE.org record (CNA or CISA ADP). An arrow marks a change the record states ("CVSS → 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). "EchelonGraph re-scored" is our own recompute of this CVE's score, not an update from a source, and is not counted in the refreshes above. Most recent first.

Showing the most recent 100 of 116 rows on record for this CVE, as 98 entries (2 repeats merged).

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. 2 repeat rows among the latest 100 are merged into the row they repeat. The 16 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-13 16:57 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  2. 2026-11-12 16:34 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  3. 2026-11-11 16:41 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  4. 2026-11-10 16:45 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  5. 2026-11-09 16:36 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  6. 2026-11-08 16:41 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  7. 2026-11-07 16:40 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  8. 2026-11-06 16:39 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  9. 2026-11-05 16:38 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  10. 2026-11-04 16:37 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  11. 2026-11-03 16:49 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  12. 2026-11-02 16:46 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  13. 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  14. 2026-11-01 07:38 UTCGHSA enrichmentGHSA-g3hc-697w-wm82 · GitHub severity MODERATE
  15. 2026-11-01 07:38 UTCEchelonGraph re-scored
  16. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  17. 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  18. 2026-10-30 01:55 UTCOSV refresh
  19. 2026-10-29 16:34 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  20. 2026-10-28 16:33 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  21. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  22. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  23. 2026-10-25 16:34 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  24. 2026-10-25 13:58 UTCEchelonGraph re-scored
  25. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.7% · 51st percentile
Show 73 more
  1. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  2. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  3. 2026-10-22 13:46 UTCEchelonGraph re-scored
  4. 2026-10-21 16:34 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  5. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  6. 2026-10-19 16:33 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  7. 2026-10-18 16:33 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  8. 2026-10-18 03:09 UTCEchelonGraph re-scored
  9. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  10. 2026-10-16 16:44 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  11. 2026-10-15 16:33 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  12. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  13. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  14. 2026-10-12 16:35 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  15. 2026-10-12 14:56 UTCEchelonGraph re-scored
  16. 2026-10-11 19:20 UTCEchelonGraph re-scored
  17. 2026-10-11 16:36 UTCEchelonGraph re-scored
  18. 2026-10-11 13:54 UTCEchelonGraph re-scored
  19. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  20. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  21. 2026-10-10 05:57 UTCEchelonGraph re-scored
  22. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  23. 2026-10-09 06:19 UTCEchelonGraph re-scored
  24. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  25. 2026-10-08 06:41 UTCEchelonGraph re-scored
  26. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  27. 2026-10-07 07:04 UTCEchelonGraph re-scored
  28. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  29. 2026-10-06 07:24 UTCEchelonGraph re-scored
  30. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  31. 2026-10-05 05:14 UTCEchelonGraph re-scored
  32. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  33. 2026-10-04 05:37 UTCEchelonGraph re-scored
  34. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  35. 2026-10-03 06:00 UTCEchelonGraph re-scored
  36. 2026-10-02 17:57 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  37. 2026-10-02 06:11 UTCEchelonGraph re-scored
  38. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  39. 2026-10-01 05:33 UTCEchelonGraph re-scored
  40. 2026-09-30 15:04 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  41. 2026-09-30 05:56 UTCEchelonGraph re-scored
  42. 2026-09-29 06:00 UTCEchelonGraph re-scored
  43. 2026-09-28 13:52 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  44. 2026-09-28 06:23 UTCEchelonGraph re-scored
  45. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  46. 2026-09-27 06:47 UTCEchelonGraph re-scored
  47. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  48. 2026-09-26 07:09 UTCEchelonGraph re-scored
  49. 2026-09-24 19:27 UTCEchelonGraph re-scored
  50. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  51. 2026-09-23 19:50 UTCEchelonGraph re-scored
  52. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  53. 2026-09-22 20:04 UTCEchelonGraph re-scored
  54. 2026-09-22 16:01 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  55. 2026-09-21 21:09 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  56. 2026-09-20 20:42 UTCEchelonGraph re-scored
  57. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  58. 2026-09-19 21:04 UTCEchelonGraph re-scored
  59. 2026-09-18 21:26 UTCEchelonGraph re-scored
  60. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  61. 2026-09-17 20:47 UTCEchelonGraph re-scored
  62. 2026-09-16 18:44 UTCEchelonGraph re-scored
  63. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  64. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  65. 2026-09-15 18:53 UTCEchelonGraph re-scored
  66. 2026-09-15 03:12 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  67. 2026-09-13 19:39 UTCEchelonGraph re-scored
  68. 2026-09-12 20:02 UTCEchelonGraph re-scored
  69. 2026-09-11 20:25 UTCEchelonGraph re-scored
  70. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  71. 2026-09-10 20:48 UTCEchelonGraph re-scored
  72. 2026-09-08 23:29 UTCEchelonGraph re-scored
  73. 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.5% · 41st percentile

Frequently asked(5)

What is CVE-2026-81887?
CVE-2026-81887 is a medium-severity vulnerability; its CVE record was published on August 31, 2026. Livewire is a full-stack framework for Laravel. From 3.0.0-beta.1 until 3.8.3 and 4.3.4, the dot-notated query-string parser in js/plugins/history/index.js, including fromQueryString() and insertDotNotatedValueIntoData(), accepts the proto, constructor, and prototype path segments and creates…
When was the CVE record for CVE-2026-81887 published?
The CVE record for CVE-2026-81887 was published on August 31, 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 9, 2026; the record at its source may have been updated since.
Is CVE-2026-81887 actively exploited?
CVE-2026-81887 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.7% probability of exploitation in the next 30 days (53rd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-81887?
CVE-2026-81887 has a CVSS base score of 5.1 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-81887?
A fix for CVE-2026-81887 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-81887 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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