CVE-2026-42563

HIGHPre-NVD 7.77.7—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.7 under the CNA's CVSS (NVD's own analysis pending). EPSS exploit probability: 0.6%, top 57% 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: cna:github_m, epss
Elevated
7.7
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 1%CVSS: 7.7Exploit: NoneExposed: 0

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

Dulwich is a pure-Python implementation of the Git file formats and protocols. Starting in version 0.24.0 and prior to version 1.2.5, Dulwich's ProcessMergeDriver substitutes the file path (from the git tree, controllable by an attacker via a malicious branch) into the merge driver command via the %P placeholder and executes it with subprocess.run(..., shell=True). An attacker who can cause a victim to merge an untrusted branch can achieve arbitrary command execution by crafting malicious file paths. Version 1.2.5 fixes the issue.

CVSS v3
7.7
EG Score
7.7(medium)
EPSS
42.5%
KEV
Not listed

Published

May 28, 2026

Last Modified

June 12, 2026

Advisory Details (3)

Auto-updated Jun 11, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github_release, github.
github Patch Available🟡 PoC Available

Command Injection via Merge Driver Path · Advisory · jelmer/dulwich · GitHub

https://github.com/jelmer/dulwich/security/advisories/GHSA-9277-mp7x-85jf
github_release Patch Available

dulwich 1.2.5

Patch available: jelmer/dulwich dulwich-1.2.5

https://github.com/jelmer/dulwich/releases/tag/dulwich-1.2.5
github_commit Patch Available

commit e3331b3b3a12 (jelmer/dulwich)

Patch available: jelmer/dulwich dulwich-1.2.5 (contains commit e3331b3b3a12)

https://github.com/jelmer/dulwich/commit/e3331b3b3a122fc313460182f928f59723580b7b

Vendor Advisories for CVE-2026-42563(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
dulwich0.24.0 ... 1.2.4 (21 versions)1.2.5—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 10× in last 7d / 57× 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. 2026-07-16 02:25 UTCEG score recompute
  2. 2026-07-15 16:57 UTCEPSS rescore
  3. 2026-07-15 02:00 UTCEPSS rescore
  4. 2026-07-14 17:35 UTCEG score recompute
  5. 2026-07-13 22:30 UTCEPSS rescore
  6. 2026-07-13 06:13 UTCEPSS rescore
  7. 2026-07-12 05:46 UTCEPSS rescore
  8. 2026-07-11 18:33 UTCEG score recompute
  9. 2026-07-11 08:27 UTCEPSS rescore
  10. 2026-07-09 19:10 UTCEPSS rescore
  11. 2026-07-08 17:35 UTCEG score recompute
  12. 2026-07-08 15:15 UTCEPSS rescore
  13. 2026-07-07 13:46 UTCEPSS rescore
  14. 2026-07-06 16:27 UTCEPSS rescore
  15. 2026-07-06 16:27 UTCEPSS rescore
  16. 2026-07-06 02:23 UTCEPSS rescore
  17. 2026-07-06 02:23 UTCEPSS rescore
  18. 2026-07-05 02:30 UTCEPSS rescore
  19. 2026-07-04 06:31 UTCEPSS rescore
  20. 2026-07-02 21:40 UTCEG score recompute
  21. 2026-07-02 05:00 UTCEG score recompute
  22. 2026-07-01 15:06 UTCEPSS rescore
  23. 2026-07-01 14:50 UTCEG score recompute
  24. 2026-07-01 01:54 UTCEG score recompute
  25. 2026-06-30 23:22 UTCEPSS rescore
Show 50 more
  1. 2026-06-30 02:18 UTCEG score recompute
  2. 2026-06-29 14:06 UTCEPSS rescore
  3. 2026-06-29 13:24 UTCEG score recompute
  4. 2026-06-28 20:28 UTCEG score recompute
  5. 2026-06-28 14:07 UTCEPSS rescore
  6. 2026-06-28 07:19 UTCEG score recompute
  7. 2026-06-28 04:56 UTCEPSS rescore
  8. 2026-06-27 18:19 UTCEG score recompute
  9. 2026-06-27 05:23 UTCEG score recompute
  10. 2026-06-27 03:08 UTCEPSS rescore
  11. 2026-06-26 16:25 UTCEG score recompute
  12. 2026-06-25 20:07 UTCEG score recompute
  13. 2026-06-25 13:49 UTCEPSS rescore
  14. 2026-06-25 13:49 UTCEPSS rescore
  15. 2026-06-25 07:13 UTCEG score recompute
  16. 2026-06-24 15:45 UTCEG score recompute
  17. 2026-06-24 14:05 UTCEPSS rescore
  18. 2026-06-23 21:33 UTCEPSS rescore
  19. 2026-06-22 14:25 UTCEPSS rescore
  20. 2026-06-22 14:25 UTCEPSS rescore
  21. 2026-06-21 14:56 UTCEPSS rescore
  22. 2026-06-21 14:56 UTCEPSS rescore
  23. 2026-06-21 01:59 UTCEPSS rescore
  24. 2026-06-19 19:25 UTCEPSS rescore
  25. 2026-06-18 22:50 UTCEG score recompute
  26. 2026-06-18 17:52 UTCEPSS rescore
  27. 2026-06-18 17:52 UTCEPSS rescore
  28. 2026-06-18 02:33 UTCEG score recompute
  29. 2026-06-17 17:53 UTCEPSS rescore
  30. 2026-06-17 13:39 UTCEG score recompute
  31. 2026-06-17 00:44 UTCEG score recompute
  32. 2026-06-16 17:52 UTCEPSS rescore
  33. 2026-06-16 11:49 UTCEG score recompute
  34. 2026-06-15 22:55 UTCEG score recompute
  35. 2026-06-15 17:49 UTCEPSS rescore
  36. 2026-06-15 10:02 UTCEG score recompute
  37. 2026-06-14 21:07 UTCEG score recompute
  38. 2026-06-14 08:13 UTCEG score recompute
  39. 2026-06-13 23:00 UTCEPSS rescore
  40. 2026-06-13 19:19 UTCEG score recompute
  41. 2026-06-13 04:47 UTCEG score recompute
  42. 2026-06-12 23:12 UTCEPSS rescore
  43. 2026-06-12 23:12 UTCEPSS rescore
  44. 2026-06-12 15:53 UTCEG score recompute
  45. 2026-06-12 02:57 UTCEG score recompute
  46. 2026-06-11 14:04 UTCEG score recompute
  47. 2026-06-11 14:00 UTCEPSS rescore
  48. 2026-06-11 01:10 UTCEG score recompute▲ 7.70
  49. 2026-06-11 01:09 UTCNVD updateCVSS v3 → 7.7 · CVSS v4 → 7.7
  50. 2026-05-28 23:06 UTCEG score recompute

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-42563?
CVE-2026-42563 is a high vulnerability published on May 28, 2026. Dulwich is a pure-Python implementation of the Git file formats and protocols. Starting in version 0.24.0 and prior to version 1.2.5, Dulwich's ProcessMergeDriver substitutes the file path (from the git tree, controllable by an attacker via a malicious branch) into the merge driver command via the…
When was CVE-2026-42563 disclosed?
CVE-2026-42563 was first published in the National Vulnerability Database on May 28, 2026, with the most recent update on June 12, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-42563 actively exploited?
CVE-2026-42563 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 42.5% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-42563?
CVE-2026-42563 has a CVSS v4.0 base score of 7.7 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-42563?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-42563, 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-2026-42563

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