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Crypt\Application · Leont

CVE-2026-2597

HIGH · 7.5 CVSS v3.1 Published 2026-02-27
Fix available
A fix is available. Upgrade to 0.010 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

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 · unedited
Crypt::SysRandom::XS versions before 0.010 for Perl is vulnerable to a heap buffer overflow in the XS function random_bytes(). The function does not validate that the length parameter is non-negative. If a negative value (e.g. -1) is supplied, the expression length + 1u causes an integer wraparound, resulting in a zero-byte allocation. The subsequent call to chosen random function (e.g. getrandom) passes the original negative value, which is implicitly converted to a large unsigned value (typically SIZE_MAX). This can result in writes beyond the allocated buffer, leading to heap memory corruption and application crash (denial of service). In common usage, the length argument is typically hardcoded by the caller, which reduces the likelihood of attacker-controlled exploitation. Applications that pass untrusted input to this parameter may be affected.

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 confidence

Crypt::SysRandom::XS Perl module before v0.010 contains a heap buffer overflow in random_bytes() due to missing validation of the length parameter. When a negative value is passed, integer wraparound (length + 1u) results in a zero-byte allocation, then the original negative value is implicitly converted to SIZE_MAX for the underlying random function call, causing out-of-bounds writes and heap corruption.

MitigationUpgrade Crypt::SysRandom::XS to version 0.010 or later which includes proper input validation. If upgrade is not immediately possible, audit all call sites passing length arguments to random_bytes() to ensure only non-negative values are used.

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
Crypt\Application
Affected:< 0.010

CVSS 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
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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 checks

Work through these to decide whether this CVE applies to you.

  1. Identify installed Crypt::SysRandom::XS version
    Run 'perl -MCrypt::SysRandom::XS -e "print $Crypt::SysRandom::XS::VERSION"' or check via cpan/CPANminus: 'cpan -D Crypt::SysRandom::XS' or 'cpanm --info Crypt::SysRandom::XS'
    Affected if The version is blank, missing, or less than 0.010 (e.g., 0.009, 0.008, etc.)
  2. Locate all Perl scripts using random_bytes()
    Search source code repositories or deployed files for 'random_bytes(' pattern using grep: 'grep -r "random_bytes(" /path/to/code'
    Affected if Any Perl file imports and calls random_bytes() from Crypt::SysRandom::XS
  3. Audit length arguments to random_bytes() calls
    Review each call site identified in step 2 and inspect the argument passed as length (first parameter). Look for variables that could hold negative values, arithmetic that could underflow, or user-controlled input without bounds checking.
    Affected if Any call passes a potentially negative integer, a variable not guaranteed to be non-negative, or performs arithmetic on the length that could yield a negative result

You are affected if Crypt::SysRandom::XS version is below 0.010 AND your code calls random_bytes() with a length argument that can be negative.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 · scoped
Upgrade available Upgrade to 0.010 or later
Fixed in 0.010
Interim mitigation

Upgrade Crypt::SysRandom::XS to version 0.010 or later which includes proper input validation. If upgrade is not immediately possible, audit all call sites passing length arguments to random_bytes() to ensure only non-negative values are used.

Recommended fix High confidence

0.010

  1. Check current installed version: `perl -MCrypt::SysRandom::XS -e 'print $Crypt::SysRandom::XS::VERSION' "
  2. Upgrade to the latest version using a Perl module installer such as cpanm: `cpanm Crypt::SysRandom::XS`
  3. Alternatively, upgrade using CPAN shell: `perl -MCPAN -e 'install Crypt::SysRandom::XS'`
  4. Verify the upgrade was successful: `perl -MCrypt::SysRandom::XS -e 'print $Crypt::SysRandom::XS::VERSION'` (should show 0.010 or later)

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Crypt\ Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing3.0 h
  • Review / QA1.0 h
7.0 hours of engineering $1,210
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,936.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-2597 in production — separate from our analysis above.

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What this is

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What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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