Evidence used
- No CISA KEV confirmation is currently recorded.
- The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
- EPSS is 0.48% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2026
CVE-2026-45190High confidence
Net::CIDR::Lite versions before 0.24 for Perl does not properly validate IP address and CIDR mask inputs, which may allow IP ACL bypass
STIGTSP · Net::CIDR::Lite
6.5MediumCVSS 3.1
Patch only the product branches with a verified fix
Fix availability varies by productMedium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority. Verified remediation exists for at least one product or source, but 324 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityMedium→Operational priority:Medium, unchanged from published severity.unchanged
Compensating controls
- Validate the affected product branch and deploy the verified fixed release.
- Restrict the affected network interface to trusted sources where business-safe.
- Monitor vendor guidance and exploitation sources for a material change.
Verification
- Confirm that the asset runs STIGTSP Net::CIDR::Lite and falls inside the recorded affected range.
- Verify the installed build against the product-specific fixed version after deployment.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Remediation availability differs by product scope
Verified remediation exists for at least one product or source, but 324 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
- Red Hat Product Security: 324 affected or under-investigation product states without a fixed product state in the same current advisory
Distribution package intelligence
5 package statesRelease-specific package status
Debian, ubuntu findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.
Repository candidate not checked
A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.
| Distribution release | Source package | Vendor state | Fixed version | Evidence |
|---|---|---|---|---|
| Debian trixietrixie · source | libnet-cidr-lite-perl | Vendor fix publishedDebian records a fixed source-package version for this release. | 0.22-3~deb13u2 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian bookwormbookworm · source | libnet-cidr-lite-perl | Vendor fix publishedDebian records a fixed source-package version for this release. | 0.22-3~deb12u2 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian forkyforky · source | libnet-cidr-lite-perl | Vendor fix publishedDebian records a fixed source-package version for this release. | 0.24-1 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian sidsid · source | libnet-cidr-lite-perl | Vendor fix publishedDebian records a fixed source-package version for this release. | 0.24-1 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | libnet-cidr-lite-perl | Vendor fix publishedCanonical reports that a fixed source package version has been published. Repository candidate availability is not checked by BlackTree. | 0.22-2ubuntu0.24.04.2 | Canonical Ubuntu Security ↗Source updated 5 Oct 2026 |
Direct vendor intelligence
1 currentAuthoritative vendor CSAF and VEX advisories
Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.
CVE-2026-45190 · CSAF 2.0 · revision 3 · finalRed Hat Product SecurityNet::CIDR::Lite: perl: Net::CIDR::Lite: IP ACL bypass due to improper input validation
The vendor explicitly identifies these products as affected by this CVE.
- perl as a component of Red Hat Enterprise Linux 10
- perl-Attribute-Handlers as a component of Red Hat Enterprise Linux 10
- perl-AutoLoader as a component of Red Hat Enterprise Linux 10
- perl-AutoSplit as a component of Red Hat Enterprise Linux 10
- perl-B as a component of Red Hat Enterprise Linux 10
- perl-Benchmark as a component of Red Hat Enterprise Linux 10
- perl-Class-Struct as a component of Red Hat Enterprise Linux 10
- perl-Config-Extensions as a component of Red Hat Enterprise Linux 10
- perl-DBM_Filter as a component of Red Hat Enterprise Linux 10
- perl-Devel-Peek as a component of Red Hat Enterprise Linux 10
- perl-Devel-SelfStubber as a component of Red Hat Enterprise Linux 10
- perl-DirHandle as a component of Red Hat Enterprise Linux 10
- Summary
- A flaw was found in Net::CIDR::Lite, a Perl module for handling IP address ranges. This vulnerability allows a remote attacker to bypass IP Access Control Lists (ACLs) due to improper validation of IP address and CIDR (Classless Inter-Domain Routing) mask inputs. Specifically, inputs containing trailing newlines or non-ASCII digit characters are incorrectly processed, leading to a mismatch between the intended and actual IP addresses. This can cause functions like `find()` and `bin_find()` to incorrectly allow or deny access, compromising network security policies.
- Remediation
- To mitigate this issue, ensure that all IP address and CIDR mask inputs processed by applications utilizing the `Net::CIDR::Lite` Perl module are strictly sanitized. This involves removing any trailing newline characters or non-ASCII digits from the input strings before they are passed to `Net::CIDR::Lite` functions such as `add()`, `find()`, or `bin_find()`. Implementing robust input validation at the application layer will prevent the module from misinterpreting malformed inputs and bypassing intended access controls.
Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority. Verified remediation exists for at least one product or source, but 324 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
Fix availability varies by product01
What, why and how
Net::CIDR::Lite versions before 0.24 for Perl does not properly validate IP address and CIDR mask inputs, which may allow IP ACL bypass. Inputs containing a trailing newline or non-ASCII digit characters pass the validators but are then re-encoded by the parser to a different address than the input string spelled. find() and bin_find() can match or miss addresses as a result. Example: my $cidr = Net::CIDR::Lite->new(); $cidr->add("::1\n/128"); $cidr->find("::1a"); # incorrectly returns true See also CVE-2026-45191.
What
Net::CIDR::Lite versions before 0.24 for Perl does not properly validate IP address and CIDR mask inputs, which may allow IP ACL bypass. Inputs containing a trailing newline or non-ASCII digit characters pass the validators but are then re-encoded by the parser to a different address than the input string spelled. find() and bin_find() can match or miss addresses as a result. Example: my $cidr = Net::CIDR::Lite->new(); $cidr->add("::1\n/128"); $cidr->find("::1a"); # incorrectly returns true See also CVE-2026-45191.
Why
The product receives an input value that is used as a resource identifier or other type of reference, but it does not validate or incorrectly validates that the input is equivalent to a potentially-unsafe value.
How
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
What
Net::CIDR::Lite versions before 0.24 for Perl does not properly validate IP address and CIDR mask inputs, which may allow IP ACL bypass. Inputs containing a trailing newline or non-ASCII digit characters pass the validators but are then re-encoded by the parser to a different address than the input string spelled. find() and bin_find() can match or miss addresses as a result. Example: my $cidr = Net::CIDR::Lite->new(); $cidr->add("::1\n/128"); $cidr->find("::1a"); # incorrectly returns true See also CVE-2026-45191.
Why
The product receives an input value that is used as a resource identifier or other type of reference, but it does not validate or incorrectly validates that the input is equivalent to a potentially-unsafe value.
How
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
Public PoC / exploit material None recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.
- Likely attack path
- a network path → Improper Validation of Unsafe Equivalence in Input → cause the confidentiality, integrity or availability impact described by the vendor
- Attack surface
- Network
- Privileges required
- None: unauthenticated exploitation is possible
- User interaction
- None
- Attack complexity
- Low: no specialised conditions are recorded
- Security boundary
- Unchanged: impact remains within the vulnerable component's security authority
- Weakness
?
CWE means Common Weakness Enumeration: a standard category for the underlying weakness. - CWE-1289 ↗
CWE-1289: Improper Validation of Unsafe Equivalence in Input. The product receives an input value that is used as a resource identifier or other type of reference, but it does not validate or incorrectly validates that the input is equivalent to a potentially-unsafe value.
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:LCommon Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.ILowIntegrity impact: A successful attack can cause a limited loss.ALowAvailability impact: A successful attack can cause a limited loss.- Post-exploitation / living off the land
- No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
03
Patch and workaround
Operational remediation based on structured source evidence.
- Status
?
Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change. - Fix availability varies by product
- Affected
- perl as a component of Red Hat Enterprise Linux 10
- perl-Attribute-Handlers as a component of Red Hat Enterprise Linux 10
- perl-AutoLoader as a component of Red Hat Enterprise Linux 10
- perl-AutoSplit as a component of Red Hat Enterprise Linux 10
- perl-B as a component of Red Hat Enterprise Linux 10
- perl-Benchmark as a component of Red Hat Enterprise Linux 10
- perl-Class-Struct as a component of Red Hat Enterprise Linux 10
- perl-Config-Extensions as a component of Red Hat Enterprise Linux 10
- perl-DBM_Filter as a component of Red Hat Enterprise Linux 10
- perl-Devel-Peek as a component of Red Hat Enterprise Linux 10
- perl-Devel-SelfStubber as a component of Red Hat Enterprise Linux 10
- perl-DirHandle as a component of Red Hat Enterprise Linux 10
- perl-Dumpvalue as a component of Red Hat Enterprise Linux 10
- perl-DynaLoader as a component of Red Hat Enterprise Linux 10
- perl-English as a component of Red Hat Enterprise Linux 10
- perl-Errno as a component of Red Hat Enterprise Linux 10
- perl-ExtUtils-Constant as a component of Red Hat Enterprise Linux 10
- perl-ExtUtils-Embed as a component of Red Hat Enterprise Linux 10
- perl-ExtUtils-Miniperl as a component of Red Hat Enterprise Linux 10
- perl-Fcntl as a component of Red Hat Enterprise Linux 10
- perl-File-Basename as a component of Red Hat Enterprise Linux 10
- perl-File-Compare as a component of Red Hat Enterprise Linux 10
- perl-File-Copy as a component of Red Hat Enterprise Linux 10
- perl-File-DosGlob as a component of Red Hat Enterprise Linux 10
- perl-File-Find as a component of Red Hat Enterprise Linux 10
- perl-File-stat as a component of Red Hat Enterprise Linux 10
- perl-FileCache as a component of Red Hat Enterprise Linux 10
- perl-FileHandle as a component of Red Hat Enterprise Linux 10
- perl-FindBin as a component of Red Hat Enterprise Linux 10
- perl-GDBM_File as a component of Red Hat Enterprise Linux 10
- and 294 more
- Action
- Use the product-specific evidence above. Patch only products with a verified fixed release, and keep every affected or under-investigation state without a matching fix in the remediation queue.
- Workaround
- To mitigate this issue, ensure that all IP address and CIDR mask inputs processed by applications utilizing the `Net::CIDR::Lite` Perl module are strictly sanitized. This involves removing any trailing newline characters or non-ASCII digits from the input strings before they are passed to `Net::CIDR::Lite` functions such as `add()`, `find()`, or `bin_find()`. Implementing robust input validation at the application layer will prevent the module from misinterpreting malformed inputs and bypassing intended access controls.
04
Evidence and provenance
Published 10 May 2026 · Last source change 12 May 2026, 14:31 UTC · CWE-1289 · Improper Validation of Unsafe Equivalence in Input
CVE recordCVE.org · 5.2
CVSS sourceCISA ADP
EPSS source FIRST · tracked since 2026-08-14
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2026-28998
Product sourceVendor CSAF · Red Hat Product Security
Remediation sourceVendor CSAF · Red Hat Product Security
CWE sourceCNA
NVD statusNVD not scheduled
Core structured fields are present and their contributing authorities are shown above.
Material change intelligence
View recent updates ↗What changed after publication
- Affected versionsThe structured affected or fixed version information changed.Red Hat Product Security ↗
- Before
- perl as a component of Red Hat Enterprise Linux 10; perl-Attribute-Handlers as a component of Red Hat Enterprise Linux 10; perl-AutoLoader as a component of Red Hat Enterprise Linux 10; perl-AutoSplit as a component of Red Hat Enterprise Linux 10; perl-B as a component of Red Hat Enterprise Linux 10; perl-Benchmark as a component of Red Hat Enterprise Linux 10; perl-Class-Struct as a component of Red Hat Enterprise Linux 10; perl-Config-Extensions as a component of Red Hat Enterprise Linux 10; perl-DBM_Filter as a component of Red Hat Enterprise Linux 10; perl-Devel-Peek as a component of Red Hat Enterprise Linux 10; perl-Devel-SelfStubber as a component of Red Hat Enterprise Linux 10; perl-DirHandle as a component of Red Hat Enterprise Linux 10; perl-Dumpvalue as a component of Red Hat Enterprise Linux 10; perl-DynaLoader as a component of Red Hat Enterprise Linux 10; perl-English as a component of Red Hat Enterprise Linux 10; perl-Errno as a component of Red Hat Enterprise Linux 10; perl-ExtUtils-Constant as a component of Red Hat Enterprise Linux 10; perl-ExtUtils-Embed as a component of Red Hat Enterprise Linux 10; perl-ExtUtils-Miniperl as a component of Red Hat Enterprise Linux 10; perl-Fcntl as a component of Red Hat Enterprise Linux 10; perl-File-Basename as a component of Red Hat Enterprise Linux 10; perl-File-Compare as a component of Red Hat Enterprise Linux 10; perl-File-Copy as a component of Red Hat Enterprise Linux 10; perl-File-DosGlob as a component of Red Hat Enterprise Linux 10; perl-File-Find as a component of Red Hat Enterprise Linux 10; perl-File-stat as a component of Red Hat Enterprise Linux 10; perl-FileCache as a component of Red Hat Enterprise Linux 10; perl-FileHandle as a component of Red Hat Enterprise Linux 10; perl-FindBin as a component of Red Hat Enterprise Linux 10; perl-GDBM_File as a component of Red Hat Enterprise Linux 10; and 293 more
- After
- perl as a component of Red Hat Enterprise Linux 10; perl-Attribute-Handlers as a component of Red Hat Enterprise Linux 10; perl-AutoLoader as a component of Red Hat Enterprise Linux 10; perl-AutoSplit as a component of Red Hat Enterprise Linux 10; perl-B as a component of Red Hat Enterprise Linux 10; perl-Benchmark as a component of Red Hat Enterprise Linux 10; perl-Class-Struct as a component of Red Hat Enterprise Linux 10; perl-Config-Extensions as a component of Red Hat Enterprise Linux 10; perl-DBM_Filter as a component of Red Hat Enterprise Linux 10; perl-Devel-Peek as a component of Red Hat Enterprise Linux 10; perl-Devel-SelfStubber as a component of Red Hat Enterprise Linux 10; perl-DirHandle as a component of Red Hat Enterprise Linux 10; perl-Dumpvalue as a component of Red Hat Enterprise Linux 10; perl-DynaLoader as a component of Red Hat Enterprise Linux 10; perl-English as a component of Red Hat Enterprise Linux 10; perl-Errno as a component of Red Hat Enterprise Linux 10; perl-ExtUtils-Constant as a component of Red Hat Enterprise Linux 10; perl-ExtUtils-Embed as a component of Red Hat Enterprise Linux 10; perl-ExtUtils-Miniperl as a component of Red Hat Enterprise Linux 10; perl-Fcntl as a component of Red Hat Enterprise Linux 10; perl-File-Basename as a component of Red Hat Enterprise Linux 10; perl-File-Compare as a component of Red Hat Enterprise Linux 10; perl-File-Copy as a component of Red Hat Enterprise Linux 10; perl-File-DosGlob as a component of Red Hat Enterprise Linux 10; perl-File-Find as a component of Red Hat Enterprise Linux 10; perl-File-stat as a component of Red Hat Enterprise Linux 10; perl-FileCache as a component of Red Hat Enterprise Linux 10; perl-FileHandle as a component of Red Hat Enterprise Linux 10; perl-FindBin as a component of Red Hat Enterprise Linux 10; perl-GDBM_File as a component of Red Hat Enterprise Linux 10; and 294 more
Technical terms and abbreviations used in this report
- CVE
- Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
- CVSS
- Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
- EPSS
- Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
- CWE
- Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
- CNA
- CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
- CISA ADP
- Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
- NVD
- National Vulnerability Database: NIST's enrichment service for CVE records.
- CERT / CSIRT
- A computer security incident response team that publishes warnings or coordinates incident response.
- PoC
- Proof of concept: public material that demonstrates or helps reproduce exploitation.
- CSAF
- Common Security Advisory Framework: a machine-readable format for security advisories.
- LoTL
- Living off the land: abuse of legitimate tools or system functions during an attack.