CVE-2015-7826
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 · uneditedbotan 1.11.x before 1.11.22 improperly handles wildcard matching against hostnames, which might allow remote attackers to have unspecified impact via a valid X.509 certificate, as demonstrated by accepting *.example.com as a match for bar.foo.example.com.
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 confidenceThe botan cryptographic library versions 1.11.x before 1.11.22 contains a flaw in X.509 certificate hostname verification where wildcard pattern matching incorrectly accepts `*.example.com` as valid for multi-level subdomains like `bar.foo.example.com`. The wildcard matching logic only checks for the presence of the pattern suffix rather than verifying it matches exactly one label level, allowing attackers with a valid certificate for a subdomain to impersonate nested subdomains.
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<= 1.11.21CVSS 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
- High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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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Identify if Botan library is in useSearch for botan library files or headers in the system, or examine application dependencies (e.g., check for 'botan' in installed packages, shared libraries, or application dependency manifests)Affected if Botan cryptographic library version 1.11.x up to and including 1.11.21 is installed and used by the application
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Determine installed Botan versionUse package manager queries (dpkg -l, rpm -qi, or similar), check library file version info, or inspect Botan version header file if source is availableAffected if The installed version is 1.11.x where x is 21 or lower (versions prior to 1.11.22)
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Verify application uses Botan for TLS/X.509 validationExamine application code or configuration to confirm it links against Botan and performs certificate hostname validation using Botan APIsAffected if The application relies on Botan library functions for X.509 certificate chain and hostname verification
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Check for wildcard certificate usageReview deployed certificates or application logs to identify if wildcard certificates (e.g., *.example.com) are used in the environmentAffected if Wildcard certificates are used in connections validated by the affected Botan version
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Inspect TLS/SSL connection behaviorIf possible, test or monitor TLS connections from the application to hosts with multi-level subdomains (e.g., bar.foo.example.com) against a certificate valid only for *.example.com - the application may accept invalid connectionsAffected if The application accepts certificate hostnames that should be rejected under proper wildcard matching (e.g., accepts *.example.com for bar.foo.example.com)
A user is affected if Botan library version 1.11.21 or earlier is installed and used by an application that validates X.509 certificate hostnames against wildcard certificates for nested subdomains.
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 · scopedUpgrade botan library to version 1.11.22 or later. For applications using the library, recompile and redeploy with the patched version. If immediate patching is not possible, implement additional hostname validation checks in application code before trusting certificate hostnames.
Botan 1.11.22 or later
- Check the current installed version of Botan (e.g., using package manager or build system)
- Upgrade Botan to version 1.11.22 or later from the official source (botan.randombit.net)
- If using a package manager (apt, yum, brew, etc.), update to the latest available package that includes version 1.11.22 or newer
- If building from source, download and build Botan 1.11.22 or a later stable release
- Rebuild any applications that link against the Botan library to ensure they use the updated version
- Verify the upgrade was successful by checking the installed Botan version
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation4.0 h
- Implementation8.0 h
- Testing8.0 h
- Review / QA4.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2015-7826 — 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-2015-7826 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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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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