CVE-2017-2491

HIGHNVD 8.88.8—
EchelonGraph scoreMEDIUM confidence

Score 8.8 from GitHub Security Advisory (severity: HIGH) published 2022-05-13. NVD baseline CVSS 8.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Weaponized
8.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 8%CVSS: 8.8Exploit: NoneExposed: 0

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

Use after free vulnerability in the String.replace method JavaScriptCore in Apple Safari in iOS before 10.3 allows remote attackers to execute arbitrary code via a crafted web page, or a crafted file.

CVSS v3
8.8
EG Score
8.8(medium)
EPSS
94.1%
KEV
Not listed

Published

June 27, 2017

Last Modified

May 13, 2026

Advisory Details (4)

Auto-updated May 22, 2026
🔬 Proof of concept available. No patch confirmed yet.
generic🟡 PoC Available

Apple Safari 10.0.3 - 'JSC::CachedCall' Use-After-Free - macOS remote Exploit

https://www.exploit-db.com/exploits/41964/
generic

About the security content of iOS 10.3 - Apple Support

https://support.apple.com/en-us/HT207617
generic

ZDI-17-321 | Zero Day Initiative

http://www.zerodayinitiative.com/advisories/ZDI-17-321
generic
http://www.securityfocus.com/bid/98316

Data Freshness Timeline

(refreshed 9× in last 7d / 35× 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. 2026-07-07 13:42 UTCEPSS rescore
  2. 2026-07-06 02:20 UTCEPSS rescore
  3. 2026-07-06 02:20 UTCEPSS rescore
  4. 2026-07-05 02:27 UTCEPSS rescore
  5. 2026-07-04 06:28 UTCEPSS rescore
  6. 2026-07-02 16:54 UTCEPSS rescore
  7. 2026-07-01 15:02 UTCEPSS rescore
  8. 2026-06-30 23:19 UTCEPSS rescore
  9. 2026-06-30 23:19 UTCEPSS rescore
  10. 2026-06-29 14:03 UTCEPSS rescore
  11. 2026-06-28 04:53 UTCEPSS rescore
  12. 2026-06-27 03:06 UTCEPSS rescore
  13. 2026-06-27 03:05 UTCEPSS rescore
  14. 2026-06-25 13:47 UTCEPSS rescore
  15. 2026-06-24 14:02 UTCEPSS rescore
  16. 2026-06-24 14:02 UTCEPSS rescore
  17. 2026-06-23 21:30 UTCEPSS rescore
  18. 2026-06-22 14:23 UTCEPSS rescore
  19. 2026-06-22 14:23 UTCEPSS rescore
  20. 2026-06-21 01:57 UTCEPSS rescore
  21. 2026-06-21 01:57 UTCEPSS rescore
  22. 2026-06-19 19:23 UTCEPSS rescore
  23. 2026-06-19 19:23 UTCEPSS rescore
  24. 2026-06-18 17:50 UTCEPSS rescore
  25. 2026-06-17 17:50 UTCEPSS rescore
Show 46 more
  1. 2026-06-16 17:50 UTCEPSS rescore
  2. 2026-06-16 17:50 UTCEPSS rescore
  3. 2026-06-15 17:45 UTCEPSS rescore
  4. 2026-06-14 23:14 UTCEPSS rescore
  5. 2026-06-13 22:57 UTCEPSS rescore
  6. 2026-06-12 23:09 UTCEPSS rescore
  7. 2026-06-10 22:15 UTCEPSS rescore
  8. 2026-06-10 13:19 UTCEPSS rescore
  9. 2026-06-08 14:14 UTCEPSS rescore
  10. 2026-06-08 14:14 UTCEPSS rescore
  11. 2026-06-07 15:22 UTCEPSS rescore
  12. 2026-06-07 15:22 UTCEPSS rescore
  13. 2026-06-06 13:45 UTCEPSS rescore
  14. 2026-06-06 13:45 UTCEPSS rescore
  15. 2026-06-05 22:44 UTCEPSS rescore
  16. 2026-06-04 13:10 UTCEPSS rescore
  17. 2026-06-02 20:11 UTCEPSS rescore
  18. 2026-06-02 20:11 UTCEPSS rescore
  19. 2026-06-01 13:49 UTCEPSS rescore
  20. 2026-05-31 22:28 UTCEPSS rescore
  21. 2026-05-31 22:28 UTCEPSS rescore
  22. 2026-05-31 00:14 UTCEPSS rescore
  23. 2026-05-31 00:14 UTCEPSS rescore
  24. 2026-05-29 13:41 UTCEPSS rescore
  25. 2026-05-28 13:42 UTCEPSS rescore
  26. 2026-05-28 13:42 UTCEPSS rescore
  27. 2026-05-27 13:38 UTCEPSS rescore
  28. 2026-05-27 13:38 UTCEPSS rescore
  29. 2026-05-26 13:42 UTCEPSS rescore
  30. 2026-05-26 13:42 UTCEPSS rescore
  31. 2026-05-26 07:17 UTCEPSS rescore
  32. 2026-05-26 07:17 UTCEPSS rescore
  33. 2026-05-22 21:15 UTCEPSS rescore
  34. 2026-05-22 21:15 UTCEPSS rescore
  35. 2026-05-22 21:15 UTCEPSS rescore
  36. 2026-05-22 21:15 UTCEPSS rescore
  37. 2026-05-22 21:15 UTCEPSS rescore
  38. 2026-05-22 12:16 UTCEG score recompute
  39. 2026-05-22 12:16 UTCGHSA enrichment
  40. 2026-05-21 22:40 UTCEPSS rescore
  41. 2026-05-20 22:37 UTCEPSS rescore
  42. 2026-05-20 22:37 UTCEPSS rescore
  43. 2026-05-20 22:37 UTCEPSS rescore
  44. 2026-05-20 11:21 UTCEPSS rescore
  45. 2026-05-20 11:21 UTCEPSS rescore
  46. 2026-05-18 21:30 UTCEPSS rescore

Publicly available exploits

(1 reference)

Working exploit code is in the public domain (1 Exploit-DB entry). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • Exploit-DBEDB-41964✓ verified
    First seen May 4, 2017

    Apple Safari 10.0.3 - 'JSC::CachedCall' Use-After-Free

    Open source ↗

Frequently asked(5)

What is CVE-2017-2491?
CVE-2017-2491 is a high vulnerability published on June 27, 2017. Use after free vulnerability in the String.replace method JavaScriptCore in Apple Safari in iOS before 10.3 allows remote attackers to execute arbitrary code via a crafted web page, or a crafted file.
When was CVE-2017-2491 disclosed?
CVE-2017-2491 was first published in the National Vulnerability Database on June 27, 2017, with the most recent update on May 13, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2017-2491 actively exploited?
CVE-2017-2491 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 94.1% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2017-2491?
CVE-2017-2491 has a CVSS v3 base score of 8.8 (NVD).
How do I remediate CVE-2017-2491?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2017-2491, 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.

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