CVE-2026-89011

HIGHPre-NVD 7.17.1—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.1 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 81% 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
7.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.1Exploit: None knownExposed: 0

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

isomorphic-git before 1.42.0 contains a prototype pollution vulnerability in the getRemoteInfo function that allows a malicious Git server operator to pollute Object.prototype by advertising crafted ref names containing '__proto__' path segments during ref negotiation. Attackers controlling a Git server can advertise a specially crafted ref such as '__proto__/corsProxy' to reroute all subsequent network operations through an attacker-controlled proxy, causing isomorphic-git to invoke the victim's onAuth callback and transmit credentials to the attacker when the victim calls getRemoteInfo with an attacker-supplied URL.

CVSS v3
7.1
EG Score
7.1(medium)
EG Risk
47(Track)
EG Risk 47/100SSVC: 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
Severity71% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
19%
KEV
Not listed

Published

September 10, 2026

Last Modified

September 11, 2026

Advisory Details (5)

Auto-updated Sep 10, 2026
🔬 Proof of concept available. Patch available. Sources: github_pr, github_commit, github, github_release.
generic

isomorphic-git < 1.42.0 Prototype Pollution via getRemoteInfo | Advisories | VulnCheck

https://www.vulncheck.com/advisories/isomorphic-git-prototype-pollution-via-getremoteinfo
github_commit Patch Available

commit b3db11188523 (isomorphic-git/isomorphic-git)

Patch available: isomorphic-git/isomorphic-git v1.42.0 (contains commit b3db11188523)

https://github.com/isomorphic-git/isomorphic-git/commit/b3db111885230bac9a648e0a2312c65ca66f76eb
github_pr Patch Available

fix prototype polution

Patch available: isomorphic-git/isomorphic-git v1.42.0 (PR #2426 merged 2026-09-10)

https://github.com/isomorphic-git/isomorphic-git/pull/2426
github_release Patch Available

v1.42.0

Patch available: isomorphic-git/isomorphic-git v1.42.0

https://github.com/isomorphic-git/isomorphic-git/releases/tag/v1.42.0
github Patch Available🟡 PoC Available

Prototype Pollution via Malicious Ref Names in getRemoteInfo · Advisory · isomorphic-git/isomorphic-git · GitHub

https://github.com/isomorphic-git/isomorphic-git/security/advisories/GHSA-83vg-jxvh-fx76

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 13× in last 7d / 23× 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. 2026-09-19 18:17 UTCEG score recompute
  2. 2026-09-18 20:05 UTCEG score recompute
  3. 2026-09-18 19:28 UTCEPSS rescore
  4. 2026-09-17 21:53 UTCEG score recompute
  5. 2026-09-17 19:32 UTCEPSS rescore
  6. 2026-09-16 23:37 UTCEG score recompute
  7. 2026-09-16 14:09 UTCEPSS rescore
  8. 2026-09-16 12:31 UTCEG score recompute
  9. 2026-09-16 05:15 UTCEPSS rescore
  10. 2026-09-15 03:13 UTCEG score recompute
  11. 2026-09-15 03:12 UTCEPSS rescore
  12. 2026-09-13 17:56 UTCEG score recompute
  13. 2026-09-13 16:48 UTCEPSS rescore
  14. 2026-09-12 19:35 UTCEG score recompute
  15. 2026-09-12 15:02 UTCEPSS rescore
  16. 2026-09-11 21:23 UTCEG score recompute
  17. 2026-09-11 20:47 UTCEG score recompute
  18. 2026-09-11 18:30 UTCEG score recompute
  19. 2026-09-11 14:53 UTCEPSS rescore
  20. 2026-09-11 14:53 UTCEPSS rescore
  21. 2026-09-10 20:18 UTCEG score recompute
  22. 2026-09-10 20:00 UTCEG score recompute
  23. 2026-09-10 19:59 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-89011?
CVE-2026-89011 is a high vulnerability published on September 10, 2026. isomorphic-git before 1.42.0 contains a prototype pollution vulnerability in the getRemoteInfo function that allows a malicious Git server operator to pollute Object.prototype by advertising crafted ref names containing 'proto' path segments during ref negotiation. Attackers controlling a Git…
When was CVE-2026-89011 disclosed?
CVE-2026-89011 was first published in the National Vulnerability Database on September 10, 2026, with the most recent update on September 11, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-89011 actively exploited?
CVE-2026-89011 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 81.3% of all scored CVEs.
What is the CVSS score of CVE-2026-89011?
CVE-2026-89011 has a CVSS v3 base score of 7.1 (NVD).
How do I remediate CVE-2026-89011?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-89011, 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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