CVE-2026-55798

MEDIUMPre-NVD 4.54.5—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 4.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.1%, top 96% 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
Elevated
4.5
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 4.5Exploit: NoneExposed: 0

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

Pillow is a Python imaging library. Prior to 12.3.0, WindowsViewer.get_command() constructed a cmd.exe shell command by directly embedding a file path into an f-string without escaping and passed the result to subprocess.Popen(..., shell=True), allowing shell metacharacters in the file path to inject arbitrary cmd.exe commands. This issue is fixed in version 12.3.0.

CVSS v3
4.5
EG Score
4.5(medium)
EG Risk
36(Track)
EG Risk 36/100SSVC: 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
Severity45% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS
3.5%
KEV
Not listed

Published

July 6, 2026

Last Modified

July 7, 2026

Advisory Details (5)

Auto-updated Jul 7, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github.
github Patch Available🟡 PoC Available

WindowsViewer.get_command() OS command injection via unescaped shell path (CWE-78) · Advisory · python-pillow/Pillow · GitHub

https://github.com/python-pillow/Pillow/security/advisories/GHSA-4x4j-2g7c-83w6
github_commit Patch Available

commit b0e06caa64c1 (python-pillow/Pillow)

Patch available: python-pillow/Pillow 12.3.0 (contains commit b0e06caa64c1)

https://github.com/python-pillow/Pillow/commit/b0e06caa64c1405aa3da0bb1d2bd9a77ca22de7f
github_commit Patch Available

commit 88194166691b (python-pillow/Pillow)

Patch available: python-pillow/Pillow 12.3.0 (contains commit 88194166691b)

https://github.com/python-pillow/Pillow/commit/88194166691b7b603529b8b036ab3ab9cedd2de4
github_commit Patch Available

commit 8404ea5fe5df (python-pillow/Pillow)

Patch available: python-pillow/Pillow 12.3.0 (contains commit 8404ea5fe5df)

https://github.com/python-pillow/Pillow/commit/8404ea5fe5df40fc34aa1e51403dd6fce0778b8a
generic

Pillow/docs/releasenotes/12.3.0.rst at main · python-pillow/Pillow · GitHub

https://github.com/python-pillow/Pillow/blob/main/docs/releasenotes/12.3.0.rst

Vendor Advisories for CVE-2026-55798(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
pillow1.0 ... 9.5.0 (106 versions)12.3.0—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 9× in last 7d / 27× 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. 2026-07-23 03:20 UTCEG score recompute
  2. 2026-07-22 14:08 UTCEPSS rescore
  3. 2026-07-21 15:25 UTCEPSS rescore
  4. 2026-07-20 17:08 UTCEPSS rescore
  5. 2026-07-19 14:31 UTCEPSS rescore
  6. 2026-07-19 14:31 UTCEPSS rescore
  7. 2026-07-19 02:29 UTCEPSS rescore
  8. 2026-07-18 10:04 UTCEPSS rescore
  9. 2026-07-16 17:03 UTCEPSS rescore
  10. 2026-07-15 16:57 UTCEPSS rescore
  11. 2026-07-15 16:57 UTCEPSS rescore
  12. 2026-07-15 02:00 UTCEPSS rescore
  13. 2026-07-15 02:00 UTCEPSS rescore
  14. 2026-07-13 22:31 UTCEPSS rescore
  15. 2026-07-13 06:13 UTCEPSS rescore
  16. 2026-07-13 06:13 UTCEPSS rescore
  17. 2026-07-12 05:46 UTCEPSS rescore
  18. 2026-07-11 08:27 UTCEPSS rescore
  19. 2026-07-11 08:27 UTCEPSS rescore
  20. 2026-07-09 19:10 UTCEPSS rescore
  21. 2026-07-09 19:10 UTCEPSS rescore
  22. 2026-07-08 15:16 UTCEPSS rescore
  23. 2026-07-08 15:16 UTCEPSS rescore
  24. 2026-07-07 13:46 UTCEPSS rescore
  25. 2026-07-07 13:46 UTCEPSS rescore
Show 2 more
  1. 2026-07-06 19:07 UTCEG score recompute
  2. 2026-07-06 19:06 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-55798?
CVE-2026-55798 is a medium vulnerability published on July 6, 2026. Pillow is a Python imaging library. Prior to 12.3.0, WindowsViewer.get_command() constructed a cmd.exe shell command by directly embedding a file path into an f-string without escaping and passed the result to subprocess.Popen(..., shell=True), allowing shell metacharacters in the file path to…
When was CVE-2026-55798 disclosed?
CVE-2026-55798 was first published in the National Vulnerability Database on July 6, 2026, with the most recent update on July 7, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-55798 actively exploited?
CVE-2026-55798 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 3.5% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-55798?
CVE-2026-55798 has a CVSS v3 base score of 4.5 (NVD).
How do I remediate CVE-2026-55798?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-55798, 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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