CVE-2026-88358

MEDIUMPre-NVD 6.56.5—
EchelonGraph scoreHIGH confidence

Score 6.5 from GitHub Security Advisory published 2026-09-24. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 6.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — 4 sources updated this weekElevated
6.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 6.5Exploit: Elevated riskExposed services: Not assessed

A fix is available — apply it.

simdjson 4.6.1 contains a one-byte out-of-bounds read vulnerability in dom::parser::parse_unpadded(). A specially crafted truncated JSON document whose final structural token closes a nested array or object can cause json_iterator::walk_document() to access buf[len] after the input buffer has been exhausted. This results in a heap out-of-bounds read and may cause application termination, leading to denial of service.

CVSS v3
6.5
EG Score
6.5MEDIUMhigh confidence
EG Risk
45
EG Risk 45/100CISA SSVC

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
Severity65% × 45%
Exploitation40% × 40%
Automatability0% × 15%
CISA SSVC: Track at low or medium mission impact; Track* at high (mission-essential systems).
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.3%
EPSS %ILE
24th
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Track* at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines.

Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

September 24, 2026

Last Modified

September 29, 2026

Advisory Details (3)

Auto-updated Sep 29, 2026
Patch available. Sources: github_pr, github_commit.
generic

parse_unpadded() performs a 1-byte out-of-bounds heap read when the final JSON structural token is a nested closing bracket (CWE-125) · Issue #2815 · simdjson/simdjson · GitHub

https://github.com/simdjson/simdjson/issues/2815
github_pr Patch Available

fix: prevent parse_unpadded 1-byte OOB on truncated nested JSON

Patch available: simdjson/simdjson v5.0.0 (PR #2817 merged 2026-08-07)

https://github.com/simdjson/simdjson/pull/2817
github_commit Patch Available

commit 20b28712ffce (simdjson/simdjson)

Patch available: simdjson/simdjson v5.0.0 (contains commit 20b28712ffce)

https://github.com/simdjson/simdjson/commit/20b28712ffce8320237b75a587d35a2e89140577

Vendor Advisories for CVE-2026-88358(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 21× in last 7d / 26× 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. 2026-10-04 08:11 UTCEG score recompute
  2. 2026-10-04 08:11 UTCGHSA enrichment
  3. 2026-10-03 07:16 UTCEG score recompute
  4. 2026-10-03 07:16 UTCGHSA enrichment
  5. 2026-10-02 06:21 UTCEG score recompute
  6. 2026-10-02 06:21 UTCGHSA enrichment
  7. 2026-10-01 19:51 UTCEPSS rescore
  8. 2026-10-01 05:27 UTCEG score recompute
  9. 2026-10-01 05:27 UTCGHSA enrichment
  10. 2026-09-30 15:04 UTCEPSS rescore
  11. 2026-09-30 04:32 UTCEG score recompute
  12. 2026-09-30 04:31 UTCGHSA enrichment
  13. 2026-09-29 03:32 UTCEG score recompute
  14. 2026-09-29 03:31 UTCGHSA enrichment
  15. 2026-09-29 02:36 UTCEG score recompute▲ 6.50
  16. 2026-09-29 02:36 UTCGHSA enrichment
  17. 2026-09-29 02:35 UTCMITRE cvelistV5CVSS v3 → 6.5 · severity → MEDIUM
  18. 2026-09-28 13:52 UTCEPSS rescore
  19. 2026-09-27 16:45 UTCEG score recompute
  20. 2026-09-27 16:45 UTCGHSA enrichment
  21. 2026-09-27 13:48 UTCEPSS rescore
  22. 2026-09-26 15:59 UTCEPSS rescore
  23. 2026-09-24 21:16 UTCGHSA enrichment
  24. 2026-09-24 16:30 UTCNVD update
  25. 2026-09-24 15:47 UTCEG score recompute
Show 1 more
  1. 2026-09-24 15:46 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-88358?
CVE-2026-88358 is a medium vulnerability published on September 24, 2026. simdjson 4.6.1 contains a one-byte out-of-bounds read vulnerability in dom::parser::parseunpadded(). A specially crafted truncated JSON document whose final structural token closes a nested array or object can cause jsoniterator::walk_document() to access buf[len] after the input buffer has been…
When was CVE-2026-88358 disclosed?
CVE-2026-88358 was first published on September 24, 2026, with the most recent update on September 29, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-88358 actively exploited?
CVE-2026-88358 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (24th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-88358?
CVE-2026-88358 has a CVSS v3.1 base score of 6.5 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-88358?
A fix for CVE-2026-88358 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-88358 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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