CurlApplication · Haxx
CVE-2026-8924
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedA flaw in curl’s cookie parsing logic allows a malicious HTTP server to set 'super cookies' that bypass the Public Suffix List check. This enables an attacker-controlled origin to inject cookies that curl subsequently scopes and transmits to unrelated third-party domains.
In the news
Third-party coverageSurfaced from public web coverage — external links open in a new tab.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceA cookie parsing flaw in curl allows malicious HTTP servers to set 'super cookies' that bypass the Public Suffix List (PSL) check, enabling attacker-controlled origins to inject cookies that curl subsequently scopes and transmits to unrelated third-party domains.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
CurlApplication
>= 7.46.0, < 8.21.0CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Check installed curl versionRun `curl --version` and note the version number in the output (e.g., 7.85.0)Affected if The version shown is >= 7.46.0 AND < 8.21.0
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Confirm version comparison against affected rangeManually compare your installed version: if it starts with 7.46, 7.47, 7.48... up to 7.x or 8.0 through 8.20.x, you are in the affected rangeAffected if Your version falls between 7.46.0 (inclusive) and 8.21.0 (exclusive)
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Verify cookie handling is in useCheck if your curl commands or applications using libcurl utilize cookie flags such as -b, --cookie, -c, --cookie-jar, or CURLOPT_COOKIE/JAR options in codeAffected if Cookies are accepted or processed by curl and the version is affected, the vulnerability is reachable
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Inspect PSL enforcement contextReview curl's cookie jar or session file (if using -c/--cookie-jar) for any cookies with broad domain scopes like `.com` or `.org` that may have been set without proper PSL validationAffected if Unexpectedly broad domain-scoped cookies exist and curl version is affected, indicating exploitation may have occurred
You are affected if curl version is 7.46.0 through 8.20.x AND your environment or applications process HTTP cookies, as the PSL bypass allows improper cookie domain scoping.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped8.21.0
Update curl to the patched version that properly validates cookies against the Public Suffix List; audit affected systems for signs of cookie-based data leakage.
curl >= 8.21.0
- Check current curl version by running: curl --version
- Upgrade curl to version 8.21.0 or later using your system's package manager (e.g., apt-get update && apt-get install curl, yum update curl, or brew upgrade curl)
- Verify the upgrade was successful by running: curl --version and confirming the version is >= 8.21.0
- Test that curl now properly validates cookies against the Public Suffix List
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Curl
Scoped from the published advisory
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,600.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-8924 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-8924 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data