CVE-2025-8262Network attack vector

Denial of service via hosted-Git fragment regex

Published Jul 28, 2025 · Updated Jul 28, 2025

Inefficient regex evaluation in Yarn 1.22.0 through 1.22.22 allows attackers to hang Yarn via a crafted hosted-Git fragment. The explodeHostedGitFragment function applies two backtracking replace expressions to the entire untrusted fragment to strip its hash and protocol prefix instead of using bounded string splitting. Reachability requires a workflow to pass an attacker-controlled hosted-Git dependency fragment to Yarn; the demonstrated consequence is excessive CPU use or freezing, not data access or modification.

CVSS severity5.3
Medium
EPSS probability0.72%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Inefficient regex evaluation in Yarn 1.22.0 through 1.22.22 allows attackers to hang Yarn via a crafted hosted-Git fragment. The explodeHostedGitFragment function applies two backtracking replace expressions to the entire untrusted fragment to strip its hash and protocol prefix instead of using bounded string splitting. Reachability requires a workflow to pass an attacker-controlled hosted-Git dependency fragment to Yarn; the demonstrated consequence is excessive CPU use or freezing, not data access or modification.

The record

CVE
CVE-2025-8262
Published
Jul 28, 2025
Updated
Jul 28, 2025
Vendor
Yarn
Product
Yarn
Classifications
CWE-400, CWE-1333, T1499.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 28, 2025CVE publishedPublication date reported by the CVE source.
  2. Jul 28, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1.22.0
  2. Affected versionversion=1.22.1
  3. Affected versionversion=1.22.10
  4. Affected versionversion=1.22.11
  5. Affected versionversion=1.22.12
  6. Affected versionversion=1.22.13
  7. Affected versionversion=1.22.14
  8. Affected versionversion=1.22.15
  9. Affected versionversion=1.22.16
  10. Affected versionversion=1.22.17
  11. Affected versionversion=1.22.18
  12. Affected versionversion=1.22.19
  13. Affected versionversion=1.22.2
  14. Affected versionversion=1.22.20
  15. Affected versionversion=1.22.21
  16. Affected versionversion=1.22.22
  17. Affected versionversion=1.22.3
  18. Affected versionversion=1.22.4
  19. Affected versionversion=1.22.5
  20. Affected versionversion=1.22.6
  21. Affected versionversion=1.22.7
  22. Affected versionversion=1.22.8
  23. Affected versionversion=1.22.9

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Yarn · Yarnversion=1.22.0; version=1.22.1; version=1.22.10; version=1.22.11; version=1.22.12; version=1.22.13; version=1.22.14; version=1.22.15; version=1.22.16; version=1.22.17; version=1.22.18; version=1.22.19; version=1.22.2; version=1.22.20; version=1.22.21; version=1.22.22; version=1.22.3; version=1.22.4; version=1.22.5; version=1.22.6; version=1.22.7; version=1.22.8; version=1.22.9

Published CVSS scores

4.3VulDB CNACVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:X/RL:O/RC:C
4.0VulDB CNAAV:N/AC:L/Au:S/C:N/I:N/A:P/E:ND/RL:OF/RC:C
5.3VulDB CNACVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X
4.3VulDB CNACVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:X/RL:O/RC:C

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
CWE-1333Inefficient Regular Expression Complexity
T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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