CVE-2026-9541

MEDIUMNVD 5.35.3—
EchelonGraph scoreMEDIUM confidence

Score 5.3 from GitHub Security Advisory (severity: LOW) published 2026-05-26. NVD baseline CVSS 5.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Trending — 4 sources updated this weekElevated
5.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.3Exploit: Elevated riskExposed: 0

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

A security flaw has been discovered in Squirrel up to 3.2. Impacted is the function ReadObject of the file squirrel/sqobject.cpp of the component Cnut File Handler. Performing a manipulation results in heap-based buffer overflow. The attack is only possible with local access. The exploit has been released to the public and may be used for attacks. The project was informed of the problem early through an issue report but has not responded yet.

CVSS v3
5.3
EG Score
5.3(medium)
EG Risk
40(Track)
EG Risk 40/100SSVC: 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
Severity53% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
7%
KEV
Not listed

Published

May 26, 2026

Last Modified

July 23, 2026

Advisory Details (2)

Auto-updated Jun 14, 2026
🔬 Proof of concept available. No patch confirmed yet.
generic🟡 PoC Available

Heap buffer overflow in ReadObject via negative string length in crafted bytecode · Issue #327 · albertodemichelis/squirrel · GitHub

https://github.com/albertodemichelis/squirrel/issues/327
generic🟡 PoC Available

pocs/squirrel-sqobject-readobject-neg-len-oob at main · biniamf/pocs · GitHub

https://github.com/biniamf/pocs/tree/main/squirrel-sqobject-readobject-neg-len-oob

Vendor Advisories for CVE-2026-9541(1)

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

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 12× in last 7d / 37× 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. 2026-07-26 14:54 UTCEPSS rescore
  2. 2026-07-26 07:53 UTCEG score recompute
  3. 2026-07-26 07:53 UTCGHSA enrichment
  4. 2026-07-25 14:18 UTCEPSS rescore
  5. 2026-07-24 14:18 UTCEPSS rescore
  6. 2026-07-23 14:18 UTCEPSS rescore
  7. 2026-07-23 11:51 UTCNVD updateCVSS v4 → 1.9
  8. 2026-07-23 03:23 UTCEG score recompute
  9. 2026-07-22 14:08 UTCEPSS rescore
  10. 2026-07-21 15:25 UTCEPSS rescore
  11. 2026-07-21 15:25 UTCEPSS rescore
  12. 2026-07-20 17:08 UTCEPSS rescore
  13. 2026-07-19 14:31 UTCEPSS rescore
  14. 2026-07-19 10:22 UTCOSV refresh
  15. 2026-07-18 10:04 UTCEPSS rescore
  16. 2026-07-16 17:03 UTCEPSS rescore
  17. 2026-07-15 16:57 UTCEPSS rescore
  18. 2026-07-15 02:00 UTCEPSS rescore
  19. 2026-07-13 22:31 UTCEPSS rescore
  20. 2026-07-13 06:13 UTCEPSS rescore
  21. 2026-07-11 08:27 UTCEPSS rescore
  22. 2026-07-09 19:10 UTCEPSS rescore
  23. 2026-07-08 15:16 UTCEPSS rescore
  24. 2026-07-07 13:46 UTCEPSS rescore
  25. 2026-07-06 16:27 UTCEPSS rescore
Show 63 more
  1. 2026-07-06 02:23 UTCEPSS rescore
  2. 2026-07-05 02:31 UTCEPSS rescore
  3. 2026-07-04 06:31 UTCEPSS rescore
  4. 2026-07-01 17:05 UTCGHSA enrichment
  5. 2026-07-01 15:07 UTCEPSS rescore
  6. 2026-06-30 23:22 UTCEPSS rescore
  7. 2026-06-29 14:06 UTCEPSS rescore
  8. 2026-06-29 01:08 UTCGHSA enrichment
  9. 2026-06-28 14:07 UTCEPSS rescore
  10. 2026-06-28 04:56 UTCEPSS rescore
  11. 2026-06-27 19:01 UTCGHSA enrichment
  12. 2026-06-27 03:08 UTCEPSS rescore
  13. 2026-06-26 18:48 UTCGHSA enrichment
  14. 2026-06-25 13:50 UTCEPSS rescore
  15. 2026-06-25 12:32 UTCGHSA enrichment
  16. 2026-06-24 14:05 UTCEPSS rescore
  17. 2026-06-23 21:33 UTCEPSS rescore
  18. 2026-06-22 14:25 UTCEPSS rescore
  19. 2026-06-21 14:56 UTCEPSS rescore
  20. 2026-06-19 19:26 UTCEPSS rescore
  21. 2026-06-18 17:52 UTCEPSS rescore
  22. 2026-06-17 19:27 UTCGHSA enrichment
  23. 2026-06-17 17:53 UTCEPSS rescore
  24. 2026-06-16 17:53 UTCEPSS rescore
  25. 2026-06-16 17:28 UTCGHSA enrichment
  26. 2026-06-15 17:49 UTCEPSS rescore
  27. 2026-06-15 13:58 UTCGHSA enrichment
  28. 2026-06-14 23:18 UTCEPSS rescore
  29. 2026-06-14 13:18 UTCGHSA enrichment
  30. 2026-06-13 23:00 UTCEPSS rescore
  31. 2026-06-13 14:24 UTCGHSA enrichment
  32. 2026-06-12 23:12 UTCEPSS rescore
  33. 2026-06-12 23:12 UTCEPSS rescore
  34. 2026-06-12 15:34 UTCGHSA enrichment
  35. 2026-06-11 16:40 UTCGHSA enrichment
  36. 2026-06-11 14:00 UTCEPSS rescore
  37. 2026-06-10 22:19 UTCEPSS rescore
  38. 2026-06-10 16:47 UTCGHSA enrichment
  39. 2026-06-10 13:22 UTCEPSS rescore
  40. 2026-06-09 17:59 UTCGHSA enrichment
  41. 2026-06-08 19:10 UTCGHSA enrichment
  42. 2026-06-08 14:17 UTCEPSS rescore
  43. 2026-06-07 17:55 UTCGHSA enrichment
  44. 2026-06-07 15:25 UTCEPSS rescore
  45. 2026-06-06 19:06 UTCGHSA enrichment
  46. 2026-06-06 13:47 UTCEPSS rescore
  47. 2026-06-05 22:47 UTCEPSS rescore
  48. 2026-06-05 20:17 UTCGHSA enrichment
  49. 2026-06-05 06:10 UTCEPSS rescore
  50. 2026-06-04 21:29 UTCGHSA enrichment
  51. 2026-06-04 13:12 UTCEPSS rescore
  52. 2026-06-03 22:40 UTCGHSA enrichment
  53. 2026-06-02 23:51 UTCGHSA enrichment
  54. 2026-06-02 20:13 UTCEPSS rescore
  55. 2026-06-02 01:02 UTCGHSA enrichment
  56. 2026-06-01 13:52 UTCEPSS rescore
  57. 2026-06-01 02:12 UTCGHSA enrichment
  58. 2026-05-31 22:30 UTCEPSS rescore
  59. 2026-05-31 00:16 UTCEPSS rescore
  60. 2026-05-29 13:44 UTCEPSS rescore
  61. 2026-05-28 13:44 UTCEPSS rescore
  62. 2026-05-27 13:40 UTCEPSS rescore
  63. 2026-05-26 13:37 UTCEG score recompute

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-9541?
CVE-2026-9541 is a medium vulnerability published on May 26, 2026. A security flaw has been discovered in Squirrel up to 3.2. Impacted is the function ReadObject of the file squirrel/sqobject.cpp of the component Cnut File Handler. Performing a manipulation results in heap-based buffer overflow. The attack is only possible with local access. The exploit has been…
When was CVE-2026-9541 disclosed?
CVE-2026-9541 was first published in the National Vulnerability Database on May 26, 2026, with the most recent update on July 23, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-9541 actively exploited?
CVE-2026-9541 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 93.4% of all scored CVEs.
What is the CVSS score of CVE-2026-9541?
CVE-2026-9541 has a CVSS v3 base score of 5.3 (NVD).
How do I remediate CVE-2026-9541?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-9541, 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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