Out-of-Bounds Read in Haxx (CVE-2025-9086)
Summary
Vulnerability in Haxx (CVE-2025-9086). Risk of unauthorized operations or information disclosure. Exploitable via secure.
Original description
The description as published by the source.
- A cookie is set using the
securekeyword forhttps://target - curl is redirected to or otherwise made to speak with
http://target(same
hostname, but using clear text HTTP) using the same cookie set - The same cookie name is set - but with just a slash as path (
path='/').
Since this site is not secure, the cookie should just be ignored. - A bug in the path comparison logic makes curl read outside a heap buffer
boundary
The bug either causes a crash or it potentially makes the comparison come to
the wrong conclusion and lets the clear-text site override the contents of the
secure cookie, contrary to expectations and depending on the memory contents
immediately following the single-byte allocation that holds the path.
The presumed and correct behavior would be to plainly ignore the second set of
the cookie since it was already set as secure on a secure host so overriding
it on an insecure host should not be okay.
Source: OSV.dev (Open Source Vulnerabilities) NVD GitHub Advisory OSV
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2025-9086 has been found in Haxx.
Attackers can target a specific entry point like secure over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 7.5/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Haxx CVE-2025-9086" on the vendor's site.
CVE-2025-9086 (Haxx) — CWE-125 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: secure
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Out-of-bounds read (CWE-125) exists in Haxx. Attackers reach the vulnerable code path via secure without authentication.
Check the vendor advisory for the affected versions of Haxx. Attack surface: secure.
Severity: High (CVSS 7.5/10). Risk of unauthorized operations or information disclosure.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'Haxx' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'Haxx' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
Haxxを grep し、稼働しているサービス・バージョンを把握する。 -
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Alpine Linux ALPINE-CVE-2025-9086 curl Fixed in: 8.14.1-r2
- Debian DEBIAN-CVE-2025-9086 curl Fixed in: 8.14.1-2+deb13u1
References
- advisory lists.debian.org
- exploit hackerone.com
- patch curl.se
- patch curl.se
- patch openwall.com
- web cert-portal.siemens.com
- web cert-portal.siemens.com
- web nvd.nist.gov
- web github.com