CVE-2025-25290Public exploitNetwork attack vector

Service hang via catastrophic link-header backtracking

Published Feb 14, 2025 · Updated Jan 16, 2026

ReDoS in fetchWrapper in Octokit @octokit/request 1.0.0 through 8.4.0 and 9.0.0-beta.1 through 9.2.0 allows remote attackers to hang services. When a response signals deprecation, fetchWrapper applies an unbounded capture regex to its Link header; repeated opening brackets force catastrophic backtracking. An attacker must cause an application to consume the crafted response header, producing excessive CPU use that can leave its process unresponsive or crash it.

CVSS severity5.3
Medium
EPSS probability0.78%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

ReDoS in fetchWrapper in Octokit @octokit/request 1.0.0 through 8.4.0 and 9.0.0-beta.1 through 9.2.0 allows remote attackers to hang services. When a response signals deprecation, fetchWrapper applies an unbounded capture regex to its Link header; repeated opening brackets force catastrophic backtracking. An attacker must cause an application to consume the crafted response header, producing excessive CPU use that can leave its process unresponsive or crash it.

The record

CVE
CVE-2025-25290
Published
Feb 14, 2025
Updated
Jan 16, 2026
Vendor
Octokit
Product
@octokit/request
Classifications
CWE-1333, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 14, 2025CVE publishedPublication date reported by the CVE source.
  2. Jan 16, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=>= 1.0.0, < 9.2.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Octokit · @octokit/requestversion=>= 1.0.0, < 9.2.1

Published CVSS scores

5.3GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-1333Inefficient Regular Expression Complexity
T1499.004Application or System Exploitation

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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