CVE-2026-52843

CRITICALPre-NVD 9.39.3—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2%, top 93% 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
9.3
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 9.3Exploit: NoneExposed: 0

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

Lightpanda is a headless browser designed for AI and automation. Prior to 0.2.9, Lightpanda fetch() and XMLHttpRequest unconditionally attached session cookies to every HTTP request, ignoring credentials: omit, credentials: same-origin, credentials: include, and XMLHttpRequest.withCredentials, allowing an attacker-controlled origin in a Lightpanda session to issue authenticated cross-origin requests against a victim origin. This issue is fixed in version 0.2.9.

CVSS v3
9.3
EG Score
9.3(medium)
EG Risk
42(Track)
EG Risk 42/100SSVC: 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
Severity93% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS
7.0%
KEV
Not listed

Published

July 15, 2026

Last Modified

July 15, 2026

Advisory Details (4)

Auto-updated Jul 15, 2026
Patch available. Sources: github, github_pr, github_commit, github_release.
github_release Patch Available

0.2.9

Patch available: lightpanda-io/browser 0.2.9

https://github.com/lightpanda-io/browser/releases/tag/0.2.9
github_commit Patch Available

commit 2cdaac780bed (lightpanda-io/browser)

Patch available: lightpanda-io/browser 0.2.9 (contains commit 2cdaac780bed)

https://github.com/lightpanda-io/browser/commit/2cdaac780bed65db98bbb6ed2ad5bc6011863c76
github_pr Patch Available

`Fetch`: cookie jar should only be included for `include` and same or…

Patch available: lightpanda-io/browser 0.2.9 (PR #2155 merged 2026-04-14)

https://github.com/lightpanda-io/browser/pull/2155
github Patch Available

fetch() and XMLHttpRequest attach session cookies to cross-origin requests regardless of credentials mode · Advisory · lightpanda-io/browser · GitHub

https://github.com/lightpanda-io/browser/security/advisories/GHSA-36mm-v3c2-24cc

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 9× in last 7d / 12× 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. 2026-07-23 14:18 UTCEPSS rescore
  2. 2026-07-23 03:19 UTCEG score recompute
  3. 2026-07-22 14:08 UTCEPSS rescore
  4. 2026-07-21 15:25 UTCEPSS rescore
  5. 2026-07-20 17:08 UTCEPSS rescore
  6. 2026-07-19 14:31 UTCEPSS rescore
  7. 2026-07-19 14:31 UTCEPSS rescore
  8. 2026-07-19 02:29 UTCEPSS rescore
  9. 2026-07-18 10:04 UTCEPSS rescore
  10. 2026-07-16 17:03 UTCEPSS rescore
  11. 2026-07-15 16:29 UTCEG score recompute
  12. 2026-07-15 16:29 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-52843?
CVE-2026-52843 is a critical vulnerability published on July 15, 2026. Lightpanda is a headless browser designed for AI and automation. Prior to 0.2.9, Lightpanda fetch() and XMLHttpRequest unconditionally attached session cookies to every HTTP request, ignoring credentials: omit, credentials: same-origin, credentials: include, and XMLHttpRequest.withCredentials,…
When was CVE-2026-52843 disclosed?
CVE-2026-52843 was first published in the National Vulnerability Database on July 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-52843 actively exploited?
CVE-2026-52843 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 7.0% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-52843?
CVE-2026-52843 has a CVSS v3 base score of 9.3 (NVD).
How do I remediate CVE-2026-52843?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-52843, 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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