CVE-2026-42563

HIGHPre-NVD 7.77.7
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to the CVSS score beside it.

This high-severity CVE scores 7.7 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.8% (55th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from a secondary CVSS source
Sources: EPSS, a secondary CVSS source
Elevated
7.7EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
CISA-KEV: Not listedEPSS PROB: 0.8%CVSS: 7.7Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

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
7.7HIGHmedium confidence
EG Risk
51
EG Risk 51/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity77% × 45%
Impact severity (EG Severity): CVSS 7.7 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation40% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low, Track* at medium and Attend at high mission impact.
Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
0.8%
EPSS %ILE
55th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (7.7): severity, escalated by confirmed exploitation. This CVE's 7.7 is its impact severity (EG Severity), not escalated.

EG Severity
7.7 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.a secondary CVSS source · CVSS v3.0 or v3.1
EG Likelihood
0.8% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-17). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track* at medium mission impactTrack at low, Track* at medium and Attend at high mission impact.CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low, Track* at medium and Attend at high mission impact.

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

May 28, 2026

Last Modified

July 21, 2026

Advisory Details (3)

Auto-updated Jun 11, 2026
Patch available. Sources: github_commit, github_release, github.
GitHub advisoryMentions a patch (unverified)

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

(5 across 5 ecosystems)
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
dulwich0.20.15-1 ... 1.2.7-2 (38 versions)
  • every version on: no fix on record
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
dulwich0.21.2-1 ... 1.2.7-2 (21 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
dulwich0.22.7-1 ... 1.2.7-2 (17 versions)
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
dulwich0.22.7-1 ... 1.2.1-1 (12 versions)
  • every version up to 1.2.5-1: fixed in 1.2.5-1
—
PyPI(1)
PackageVulnerable rangeFix by version rangeDependents
dulwich0.24.0 ... 1.2.4 (21 versions)
  • 0.24.0 up to 1.2.5: fixed in 1.2.5
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 9× in last 7d / 30× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 100 of 159 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 59 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.8% · 55th percentile
  2. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.8% · 55th percentile
  3. 2026-10-18 03:40 UTCEG score recompute
  4. 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.8% · 55th percentile
  5. 2026-10-17 14:23 UTCEG score recompute
  6. 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.8% · 55th percentile
  7. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.8% · 55th percentile
  8. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.8% · 55th percentile
  9. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.8% · 55th percentile
  10. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.8% · 55th percentile
  11. 2026-10-12 16:07 UTCEG score recompute
  12. 2026-10-11 19:49 UTCEG score recompute
  13. 2026-10-11 17:03 UTCEG score recompute
  14. 2026-10-11 14:29 UTCEG score recompute
  15. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.8% · 55th percentile
  16. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.8% · 55th percentile
  17. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.8% · 55th percentile
  18. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.8% · 55th percentile
  19. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.8% · 55th percentile
  20. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.8% · 55th percentile
  21. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.8% · 54th percentile
  22. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.8% · 54th percentile
  23. 2026-10-03 14:49 UTCOSV refresh
  24. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.8% · 54th percentile
  25. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.8% · 54th percentile
Show 75 more
  1. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.8% · 54th percentile
  2. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.8% · 54th percentile
  3. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.8% · 54th percentile
  4. 2026-09-23 17:53 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  5. 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  6. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  7. 2026-09-17 19:31 UTCEPSS rescoreEPSS 0.6% · 44th percentile
  8. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.6% · 44th percentile
  9. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.6% · 44th percentile
  10. 2026-09-14 06:29 UTCEG score recompute
  11. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.6% · 44th percentile
  12. 2026-09-13 02:09 UTCOSV refresh
  13. 2026-09-12 15:01 UTCEPSS rescoreEPSS 0.6% · 44th percentile
  14. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.6% · 44th percentile
  15. 2026-09-11 09:37 UTCEPSS rescoreEPSS 0.6% · 44th percentile
  16. 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.6% · 44th percentile
  17. 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.6% · 44th percentile
  18. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.6% · 44th percentile
  19. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.6% · 44th percentile
  20. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.6% · 44th percentile
  21. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.6% · 44th percentile
  22. 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.6% · 44th percentile
  23. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.6% · 44th percentile
  24. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.6% · 43rd percentile
  25. 2026-08-28 21:41 UTCEPSS rescoreEPSS 0.6% · 43rd percentile
  26. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.6% · 43rd percentile
  27. 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.6% · 43rd percentile
  28. 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.6% · 43rd percentile
  29. 2026-08-25 04:29 UTCEG score recompute
  30. 2026-08-23 14:21 UTCEG score recompute
  31. 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.6% · 44th percentile
  32. 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.6% · 44th percentile
  33. 2026-08-20 23:40 UTCEG score recompute
  34. 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.6% · 43rd percentile
  35. 2026-08-20 10:31 UTCEG score recompute
  36. 2026-08-19 17:03 UTCEPSS rescoreEPSS 0.6% · 43rd percentile
  37. 2026-08-18 13:48 UTCEPSS rescoreEPSS 0.6% · 43rd percentile
  38. 2026-08-17 13:47 UTCEPSS rescoreEPSS 0.6% · 43rd percentile
  39. 2026-08-16 15:20 UTCEG score recompute
  40. 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.6% · 43rd percentile
  41. 2026-08-16 02:27 UTCEG score recompute
  42. 2026-08-16 02:14 UTCEPSS rescoreEPSS 0.6% · 43rd percentile
  43. 2026-08-15 02:25 UTCEG score recompute
  44. 2026-08-15 01:30 UTCEPSS rescoreEPSS 0.6% · 43rd percentile
  45. 2026-08-14 00:38 UTCEG score recompute
  46. 2026-08-13 22:00 UTCEPSS rescoreEPSS 0.6% · 43rd percentile
  47. 2026-08-12 15:45 UTCEG score recompute
  48. 2026-08-12 13:51 UTCEPSS rescoreEPSS 0.6% · 43rd percentile
  49. 2026-08-12 02:20 UTCEG score recompute
  50. 2026-08-11 13:43 UTCEPSS rescoreEPSS 0.6% · 43rd percentile
  51. 2026-08-11 13:27 UTCEG score recompute
  52. 2026-08-11 00:00 UTCEPSS rescoreEPSS 0.6% · 43rd percentile
  53. 2026-08-09 17:37 UTCEG score recompute
  54. 2026-08-09 13:46 UTCEPSS rescoreEPSS 0.6% · 43rd percentile
  55. 2026-08-09 04:44 UTCEG score recompute
  56. 2026-08-08 16:37 UTCEPSS rescoreEPSS 0.6% · 43rd percentile
  57. 2026-08-08 01:48 UTCEG score recompute
  58. 2026-08-07 00:00 UTCEG score recompute
  59. 2026-08-06 13:46 UTCEPSS rescoreEPSS 0.6% · 43rd percentile
  60. 2026-08-05 20:44 UTCEG score recompute
  61. 2026-08-05 19:17 UTCEPSS rescoreEPSS 0.6% · 43rd percentile
  62. 2026-08-04 23:22 UTCEG score recompute
  63. 2026-08-04 15:10 UTCEPSS rescoreEPSS 0.6% · 43rd percentile
  64. 2026-08-04 10:38 UTCEPSS rescoreEPSS 0.6% · 43rd percentile
  65. 2026-08-03 18:42 UTCEG score recompute
  66. 2026-08-03 10:36 UTCEPSS rescoreEPSS 0.6% · 43rd percentile
  67. 2026-08-02 03:05 UTCEG score recompute
  68. 2026-08-02 02:27 UTCEPSS rescoreEPSS 0.6% · 43rd percentile
  69. 2026-08-01 14:10 UTCEG score recompute
  70. 2026-08-01 04:16 UTCEPSS rescoreEPSS 0.6% · 43rd percentile
  71. 2026-07-31 05:59 UTCEG score recompute
  72. 2026-07-30 16:28 UTCEPSS rescoreEPSS 0.6% · 43rd percentile
  73. 2026-07-30 01:30 UTCEPSS rescoreEPSS 0.6% · 43rd percentile
  74. 2026-07-29 12:08 UTCEG score recompute
  75. 2026-07-28 15:36 UTCEPSS rescoreEPSS 0.6% · 43rd percentile

Frequently asked(5)

What is CVE-2026-42563?
CVE-2026-42563 is a high-severity vulnerability; its CVE record was 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 the CVE record for CVE-2026-42563 published?
The CVE record for CVE-2026-42563 was published on May 28, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of July 21, 2026; the record at its source may have been updated since.
Is CVE-2026-42563 actively exploited?
CVE-2026-42563 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.8% probability of exploitation in the next 30 days (55th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-42563?
CVE-2026-42563 has a CVSS base score of 7.7 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-42563?
A fix for CVE-2026-42563 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-42563 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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