CVE-2026-50558

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: 0.2%, top 84% 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.

Penelope Shell Handler is a post-exploitation shell handler for authorized security testing. Prior to 0.20.0, the Unix download() implementation in penelope.py used tar.extractall(local_download_folder) on tar archives returned by remote sessions without validating member paths, allowing a malicious or compromised session to write files outside the intended download directory and potentially overwrite ~/.penelope/peneloperc. This issue is fixed in version 0.20.0.

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
16%
KEV
Not listed

Published

July 29, 2026

Last Modified

July 29, 2026

Advisory Details (3)

Auto-updated Jul 29, 2026
🔬 Proof of concept available. Patch available. Sources: github, github_commit, github_release.
github Patch Available🟡 PoC Available

Penelope unsafe tar extraction allows arbitrary local file write via crafted session archive · Advisory · brightio/penelope · GitHub

Affected: version 0.19.3 by rejecting unsafe archive paths during extraction.

https://github.com/brightio/penelope/security/advisories/GHSA-f42x-p2mx-hm8r
github_release Patch Available

v0.20.0

Patch available: brightio/penelope v0.20.0

https://github.com/brightio/penelope/releases/tag/v0.20.0
github_commit Patch Available

commit a040afb5db32 (brightio/penelope)

Patch available: brightio/penelope v0.20.0 (contains commit a040afb5db32)

https://github.com/brightio/penelope/commit/a040afb5db32c7e80b5e8a2f9b2164cf911cfa62

Vendor Advisories for CVE-2026-50558(1)

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

Affected Packages

(1 across 1 ecosystem)
PyPI(1)
PackageVulnerable rangeFixed inDependents
penelope-shell-handler0.15.0, 0.18.0, 0.19.10.20.0—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 11× in last 7d / 49× 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. 2026-08-28 01:09 UTCEG score recompute
  2. 2026-08-27 14:25 UTCEPSS rescore
  3. 2026-08-26 22:45 UTCEG score recompute
  4. 2026-08-26 14:46 UTCEPSS rescore
  5. 2026-08-25 20:45 UTCEG score recompute
  6. 2026-08-25 13:49 UTCEPSS rescore
  7. 2026-08-24 18:34 UTCEG score recompute
  8. 2026-08-23 16:34 UTCEG score recompute
  9. 2026-08-23 00:19 UTCEPSS rescore
  10. 2026-08-22 14:35 UTCEG score recompute
  11. 2026-08-21 23:49 UTCEPSS rescore
  12. 2026-08-21 12:36 UTCEG score recompute
  13. 2026-08-20 22:55 UTCEPSS rescore
  14. 2026-08-20 10:37 UTCEG score recompute
  15. 2026-08-19 17:04 UTCEPSS rescore
  16. 2026-08-19 08:38 UTCEG score recompute
  17. 2026-08-18 13:48 UTCEPSS rescore
  18. 2026-08-18 06:39 UTCEG score recompute
  19. 2026-08-17 13:47 UTCEPSS rescore
  20. 2026-08-17 04:39 UTCEG score recompute
  21. 2026-08-16 14:56 UTCEPSS rescore
  22. 2026-08-16 02:39 UTCEG score recompute
  23. 2026-08-16 02:14 UTCEPSS rescore
  24. 2026-08-15 01:30 UTCEPSS rescore
  25. 2026-08-13 22:41 UTCEG score recompute
Show 27 more
  1. 2026-08-13 22:00 UTCEPSS rescore
  2. 2026-08-12 20:41 UTCEG score recompute
  3. 2026-08-12 13:51 UTCEPSS rescore
  4. 2026-08-11 18:42 UTCEG score recompute
  5. 2026-08-11 00:00 UTCEPSS rescore
  6. 2026-08-09 14:28 UTCEG score recompute
  7. 2026-08-09 13:46 UTCEPSS rescore
  8. 2026-08-08 16:37 UTCEPSS rescore
  9. 2026-08-08 12:29 UTCEG score recompute
  10. 2026-08-07 10:29 UTCEG score recompute
  11. 2026-08-06 13:47 UTCEPSS rescore
  12. 2026-08-06 08:30 UTCEG score recompute
  13. 2026-08-05 19:17 UTCEPSS rescore
  14. 2026-08-05 06:32 UTCEG score recompute
  15. 2026-08-04 15:10 UTCEPSS rescore
  16. 2026-08-04 10:39 UTCEPSS rescore
  17. 2026-08-04 04:29 UTCEG score recompute
  18. 2026-08-03 10:36 UTCEPSS rescore
  19. 2026-08-03 02:30 UTCEG score recompute
  20. 2026-08-02 02:27 UTCEPSS rescore
  21. 2026-08-02 00:31 UTCEG score recompute
  22. 2026-08-01 04:16 UTCEPSS rescore
  23. 2026-07-30 20:30 UTCEG score recompute
  24. 2026-07-30 16:28 UTCEPSS rescore
  25. 2026-07-29 16:24 UTCEG score recompute
  26. 2026-07-29 16:07 UTCEG score recompute
  27. 2026-07-29 16:07 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-50558?
CVE-2026-50558 is a medium vulnerability published on July 29, 2026. Penelope Shell Handler is a post-exploitation shell handler for authorized security testing. Prior to 0.20.0, the Unix download() implementation in penelope.py used tar.extractall(localdownloadfolder) on tar archives returned by remote sessions without validating member paths, allowing a malicious…
When was CVE-2026-50558 disclosed?
CVE-2026-50558 was first published in the National Vulnerability Database on July 29, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-50558 actively exploited?
CVE-2026-50558 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 83.9% of all scored CVEs.
What is the CVSS score of CVE-2026-50558?
CVE-2026-50558 has a CVSS v3 base score of 5.9 (NVD).
How do I remediate CVE-2026-50558?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-50558, 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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