CVE-2026-49858

MEDIUMPre-NVD 5.95.9—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.9 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 76% 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
5.9EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.9Exploit: None knownExposed: 0

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

API Platform Core is a system to create hypermedia-driven REST and GraphQL APIs. In versions from 2.6.0 prior to 4.1.29, 4.2.26, and 4.3.12, a missing isCacheKeySafe gate in the JSON:API and HAL item normalizers causes a cross-user attribute leak. #[ApiProperty(security: ...)] is evaluated per request to decide whether a property is exposed. The componentsCache arrays in ApiPlatform\JsonApi\Serializer\ItemNormalizer and ApiPlatform\Hal\Serializer\ItemNormalizer are keyed on $context['cache_key'], which is set unconditionally before delegating to the parent normalizer. The component structure (attributes, relationships, links) computed for one request can therefore be reused for a subsequent request whose user has a different set of accessible properties. A user with lower privileges may end up seeing the structure of properties that the security predicate would otherwise have hidden for them. This issue has been fixed in versions 4.1.29, 4.2.26, and 4.3.12.

CVSS v3
5.9
EG Score
5.9(medium)
EG Risk
31(Track)
EG Risk 31/100SSVC: 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
Severity59% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
24%
KEV
Not listed

Published

July 1, 2026

Last Modified

July 2, 2026

Advisory Details (1)

Auto-updated Jul 3, 2026
Patch available. Sources: github.
github Patch Available

Cross-user attribute leak in JSON:API and HAL item normalizers due to missing isCacheKeySafe gate · Advisory · api-platform/core · GitHub

https://github.com/api-platform/core/security/advisories/GHSA-pjhx-3c3w-9v23

Vendor Advisories for CVE-2026-49858(1)

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

Affected Packages

(3 across 1 ecosystem)
Packagist(3)
PackageVulnerable rangeFixed inDependents
api-platform/corev4.3.0 ... v4.3.7 (8 versions)4.3.8—
api-platform/halv4.3.0 ... v4.3.7 (8 versions)4.3.8—
api-platform/json-apiv4.3.0 ... v4.3.7 (8 versions)4.3.8—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 9× in last 7d / 50× 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. 2026-08-25 16:16 UTCEG score recompute
  2. 2026-08-25 13:49 UTCEPSS rescore
  3. 2026-08-24 10:50 UTCEG score recompute
  4. 2026-08-22 06:58 UTCEG score recompute
  5. 2026-08-21 23:49 UTCEPSS rescore
  6. 2026-08-21 04:46 UTCEG score recompute
  7. 2026-08-20 22:55 UTCEPSS rescore
  8. 2026-08-20 04:37 UTCEG score recompute
  9. 2026-08-19 17:04 UTCEPSS rescore
  10. 2026-08-18 23:29 UTCEG score recompute
  11. 2026-08-18 13:48 UTCEPSS rescore
  12. 2026-08-17 23:19 UTCEG score recompute
  13. 2026-08-17 13:47 UTCEPSS rescore
  14. 2026-08-16 18:32 UTCEG score recompute
  15. 2026-08-16 14:56 UTCEPSS rescore
  16. 2026-08-16 02:14 UTCEPSS rescore
  17. 2026-08-15 18:24 UTCEG score recompute
  18. 2026-08-15 01:30 UTCEPSS rescore
  19. 2026-08-14 18:15 UTCEG score recompute
  20. 2026-08-13 22:00 UTCEPSS rescore
  21. 2026-08-12 17:36 UTCEG score recompute
  22. 2026-08-12 13:51 UTCEPSS rescore
  23. 2026-08-11 17:28 UTCEG score recompute
  24. 2026-08-11 00:00 UTCEPSS rescore
  25. 2026-08-09 16:54 UTCEG score recompute
Show 53 more
  1. 2026-08-09 13:46 UTCEPSS rescore
  2. 2026-08-08 16:46 UTCEG score recompute
  3. 2026-08-08 16:37 UTCEPSS rescore
  4. 2026-08-07 16:37 UTCEG score recompute
  5. 2026-08-06 16:29 UTCEG score recompute
  6. 2026-08-06 13:47 UTCEPSS rescore
  7. 2026-08-05 19:17 UTCEPSS rescore
  8. 2026-08-05 16:20 UTCEG score recompute
  9. 2026-08-04 15:10 UTCEPSS rescore
  10. 2026-08-04 15:02 UTCEG score recompute
  11. 2026-08-04 10:39 UTCEPSS rescore
  12. 2026-08-03 14:54 UTCEG score recompute
  13. 2026-08-03 10:36 UTCEPSS rescore
  14. 2026-08-02 14:45 UTCEG score recompute
  15. 2026-08-02 02:27 UTCEPSS rescore
  16. 2026-08-01 14:36 UTCEG score recompute
  17. 2026-08-01 04:16 UTCEPSS rescore
  18. 2026-07-31 14:27 UTCEG score recompute
  19. 2026-07-30 16:28 UTCEPSS rescore
  20. 2026-07-30 14:12 UTCEG score recompute
  21. 2026-07-30 01:30 UTCEPSS rescore
  22. 2026-07-29 14:02 UTCEG score recompute
  23. 2026-07-28 15:37 UTCEPSS rescore
  24. 2026-07-28 13:53 UTCEG score recompute
  25. 2026-07-27 13:22 UTCEG score recompute
  26. 2026-07-26 14:54 UTCEPSS rescore
  27. 2026-07-26 13:13 UTCEG score recompute
  28. 2026-07-25 14:18 UTCEPSS rescore
  29. 2026-07-24 14:18 UTCEPSS rescore
  30. 2026-07-23 14:18 UTCEPSS rescore
  31. 2026-07-23 03:18 UTCEG score recompute
  32. 2026-07-22 14:08 UTCEPSS rescore
  33. 2026-07-21 15:25 UTCEPSS rescore
  34. 2026-07-20 17:08 UTCEPSS rescore
  35. 2026-07-19 14:31 UTCEPSS rescore
  36. 2026-07-19 14:31 UTCEPSS rescore
  37. 2026-07-19 02:29 UTCEPSS rescore
  38. 2026-07-18 10:04 UTCEPSS rescore
  39. 2026-07-16 17:03 UTCEPSS rescore
  40. 2026-07-15 02:00 UTCEPSS rescore
  41. 2026-07-13 22:30 UTCEPSS rescore
  42. 2026-07-13 06:13 UTCEPSS rescore
  43. 2026-07-12 05:46 UTCEPSS rescore
  44. 2026-07-11 08:27 UTCEPSS rescore
  45. 2026-07-09 19:10 UTCEPSS rescore
  46. 2026-07-08 15:16 UTCEPSS rescore
  47. 2026-07-07 13:46 UTCEPSS rescore
  48. 2026-07-06 16:27 UTCEPSS rescore
  49. 2026-07-06 02:23 UTCEPSS rescore
  50. 2026-07-05 02:30 UTCEPSS rescore
  51. 2026-07-04 06:31 UTCEPSS rescore
  52. 2026-07-01 21:08 UTCEG score recompute
  53. 2026-07-01 21:08 UTCNVD updatefirst tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-49858?
CVE-2026-49858 is a medium vulnerability published on July 1, 2026. API Platform Core is a system to create hypermedia-driven REST and GraphQL APIs. In versions from 2.6.0 prior to 4.1.29, 4.2.26, and 4.3.12, a missing isCacheKeySafe gate in the JSON:API and HAL item normalizers causes a cross-user attribute leak. #[ApiProperty(security: ...)] is evaluated per…
When was CVE-2026-49858 disclosed?
CVE-2026-49858 was first published in the National Vulnerability Database on July 1, 2026, with the most recent update on July 2, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-49858 actively exploited?
CVE-2026-49858 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 76.3% of all scored CVEs.
What is the CVSS score of CVE-2026-49858?
CVE-2026-49858 has a CVSS v3 base score of 5.9 (NVD).
How do I remediate CVE-2026-49858?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-49858, 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

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-49858

Explore →

Is Your Infrastructure Affected by CVE-2026-49858?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs