CVE-2025-9308Public exploit

Local denial of service via crafted CA file

Published Aug 21, 2025 · Updated Aug 21, 2025

Regular expression denial of service in Yarn 1.22.0 through 1.22.22 allows local users to hang the CLI via a crafted CA file. The setOptions method reads opts.cafile and splits its contents with a backtracking-prone expression; repeated BEGIN prefixes force excessive matching work. Exploitation requires control of the local CA-file configuration and its referenced file, consuming CPU and delaying or freezing the invoking Yarn process.

CVSS severity4.8
Medium
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Regular expression denial of service in Yarn 1.22.0 through 1.22.22 allows local users to hang the CLI via a crafted CA file. The setOptions method reads opts.cafile and splits its contents with a backtracking-prone expression; repeated BEGIN prefixes force excessive matching work. Exploitation requires control of the local CA-file configuration and its referenced file, consuming CPU and delaying or freezing the invoking Yarn process.

The record

CVE
CVE-2025-9308
Published
Aug 21, 2025
Updated
Aug 21, 2025
Vendor
Yarn
Product
Yarn
Classifications
CWE-1333, CWE-400, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 21, 2025CVE publishedPublication date reported by the CVE source.
  2. Aug 21, 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 vectorlocal
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

4.8VulDB CNACVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X
1.7VulDB CNAAV:L/AC:L/Au:S/C:N/I:N/A:P/E:ND/RL:ND/RC:UR
3.3VulDB CNACVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:X/RL:X/RC:R
5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
3.3VulDB CNACVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:X/RL:X/RC:R

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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No observations available

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

Weakness, pattern, technique

CWE-1333Inefficient Regular Expression Complexity
CWE-400Uncontrolled Resource Consumption
T1499Endpoint Denial of Service

Public exploit references

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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