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CVE Record

CVE-2026-5084: WebDyne::Session versions before 3.003_704 for Perl generate the session id insecurely

WebDyne::Session versions before 3.003_704 for Perl generate the session id insecurely. The session handler generates the session id from an MD5 hash seeded with a call to the built-in rand() function. The rand function is passed a maximum value based on the process id, the epoch time and the reference address of the object, but this information will have no effect on the overall quality of the seed of the message digest. The rand function is seeded by 32-bits and is predictable. It is considered unsuitable for cryptographic purposes. Predictable session ids could allow an attacker to gain access to systems. Note that WebDyne::Session versions 1.042 and earlier appear to be in separate distributions from WebDyne.

MediumCVSS 6.5Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2026-5084 affects Perl applications using WebDyne::Session before 3.003_704. The library creates session IDs using predictable randomness. If an application relies on these session IDs for login state, an attacker may be able to guess a valid session and access accounts or systems.

Executive priority

Treat as a targeted remediation item, not an emergency. Prioritize systems where WebDyne sessions protect user or administrator access, especially internet-facing services. The business concern is unauthorized access through predictable session identifiers.

Technical view

WebDyne::Session used an MD5-derived session ID seeded with Perl rand(). The CVE notes rand() is 32-bit seeded and unsuitable for cryptographic use. This maps to CWE-338 and CWE-340. CVSS is 6.5: network exploitable, low complexity, no privileges or user interaction, with low confidentiality and integrity impact.

Likely exposure

Exposure is limited to Perl applications that use WebDyne::Session versions before 3.003_704 for security-relevant sessions. Older WebDyne::Session 1.042 and earlier may be distributed separately, so dependency inventory may need both WebDyne and WebDyne::Session checks.

Exploitation context

The source bundle does not report active exploitation, and KEV status is false. Practical risk depends on whether attackers can observe or predict enough session behavior and whether the affected session IDs protect authenticated application access.

Researcher notes

The public evidence identifies insecure session ID generation and a patch reference. No public exploit status is provided in the source bundle. Packaging ambiguity exists for WebDyne::Session 1.042 and earlier, which may require separate distribution checks beyond the WebDyne package.

Mitigation direction

  • Upgrade WebDyne::Session or WebDyne to 3.003_704 or later where applicable.
  • Check vendor project guidance for separately distributed WebDyne::Session 1.042 and earlier.
  • Rotate active sessions after upgrading, if the application uses these IDs for authentication.
  • Prioritize internet-facing applications and administrative portals using WebDyne sessions.

Validation and detection

  • Inventory Perl dependencies for WebDyne and WebDyne::Session usage.
  • Confirm installed versions are 3.003_704 or later.
  • Review application code to confirm whether WebDyne::Session manages authentication sessions.
  • Verify session invalidation occurred after remediation, where operationally feasible.
  • Monitor authentication logs for unusual session reuse or account access patterns.
Prepared
Confidence
medium
Sources
6

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · low confidence lookup

CWE-338: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

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cwe · low confidence lookup

CWE-340: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

Open ATT&CK lookup
cve · low confidence lookup

CVE-2026-5084 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
Medium
CVSS
6.5 (3.1)
Known Exploited
No
Published

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

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

1CVSS vectors
3Timeline events
2ADP providers
5Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: yesTechnical Impact: partial

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
6.5CVSS 3.1MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N3.92.5CISA-ADP

Vulnerability scoring details

Base CVSS 3.1 score

6.5Medium
CVSS 3.1 vector shape for CVE-2026-5084Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

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

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
cvssV3_1other:ssvc
CVECVE Program Container

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
ASPEERWebDyne::SessionWebDyne, 0unaffected
Weakness

CWE details

CWE-338CWE-340

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.