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 0.31% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2026
CVE-2026-71855High confidence
Suricata flow: IPv4/IPv6 hash collision can reuse wrong flow state
OISF · suricata
Official source article: GitHub GHSA-FVWH-WJCQ-2586 ↗. Check the applicable product and release in the original source.
5.9MediumCVSS 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 1 structured product or package state 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 OISF suricata 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 1 structured product or package state remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
- Debian Security Tracker: 1 affected package state with no published fix
Distribution package intelligence
4 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.
Package result overrides the generic status
BlackTree has verified remediation for at least one product or source, but the relevant distribution still reports no fixed package for 1 affected package state shown here. Treat those rows as affected with no fix until that distribution publishes a fixed version.
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 | suricata | Affected, no fix publishedDebian currently tracks this release as open. | Not published in this feed | Debian Security Tracker ↗Source updated 3 Oct 2026 |
| Debian forkyforky · source | suricata | Vendor fix publishedDebian records a fixed source-package version for this release. | 1:8.0.6-1 | Debian Security Tracker ↗Source updated 3 Oct 2026 |
| Debian sidsid · source | suricata | Vendor fix publishedDebian records a fixed source-package version for this release. | 1:8.0.6-1 | Debian Security Tracker ↗Source updated 3 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | suricata | Under evaluationCanonical reports that the package might be affected and still needs evaluation or fixing. | Not published in this feed | Canonical Ubuntu Security ↗Source updated 2 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-2026-71855 · CSAF 2.0 · revision 3 · finalRed Hat Product Securitysuricata: Suricata: Detection bypass via IPv4/IPv6 hash collision
The vendor explicitly states that these products are not affected by this CVE.
- All currently supported Red Hat products
- Summary
- A flaw was found in Suricata. This flaw allows a remote attacker to cause an IPv4 and IPv6 flow to be treated as identical due to a hash collision. This occurs when their raw address words, ports, protocol, VLAN, recursion level, live device, and hash bucket align, without proper comparison of the IP family. This can lead to incorrect flow state, enabling an attacker to bypass detection mechanisms or achieve IP-only bypass.
- Remediation
- No remediation text is recorded.
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 1 structured product or package state remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
Fix availability varies by product01
What, why and how
Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. Prior to 7.0.17 and 8.0.6, src/flow-hash.c can treat an IPv4 and IPv6 flow as equal without comparing the IP family when their raw address words, ports, protocol, VLAN, recursion level, live device, and hash bucket align. An IPv6 packet can therefore reuse IPv4 flow state or the reverse, causing incorrect flowbit state, detection bypass, or IP-only bypass. This issue is fixed in versions 8.0.6 and 7.0.17.
What
Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. Prior to 7.0.17 and 8.0.6, src/flow-hash.c can treat an IPv4 and IPv6 flow as equal without comparing the IP family when their raw address words, ports, protocol, VLAN, recursion level, live device, and hash bucket align. An IPv6 packet can therefore reuse IPv4 flow state or the reverse, causing incorrect flowbit state, detection bypass, or IP-only bypass. This issue is fixed in versions 8.0.6 and 7.0.17.
Why
The product compares two entities in a security-relevant context, but the comparison is incorrect.
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
Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. Prior to 7.0.17 and 8.0.6, src/flow-hash.c can treat an IPv4 and IPv6 flow as equal without comparing the IP family when their raw address words, ports, protocol, VLAN, recursion level, live device, and hash bucket align. An IPv6 packet can therefore reuse IPv4 flow state or the reverse, causing incorrect flowbit state, detection bypass, or IP-only bypass. This issue is fixed in versions 8.0.6 and 7.0.17.
Why
The product compares two entities in a security-relevant context, but the comparison is incorrect.
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 → Incorrect Comparison → 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
- High: exploitation depends on specific conditions
- 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-697 ↗
CWE-697: Incorrect Comparison. The product compares two entities in a security-relevant context, but the comparison is incorrect.
- 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:H/PR:N/UI:N/S:U/C:N/I:H/A:NCommon 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.ACHighAttack complexity: Successful exploitation depends on specific conditions outside the attacker's direct control.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.IHighIntegrity impact: A successful attack can cause a major loss.ANoneAvailability impact: No direct loss is represented by this metric.- 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
- 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
- No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
Official vendor articles3 stored documents
Linked articles are downloaded and versioned as source evidence. A CVE mention or approved update relationship does not, by itself, verify a fix for every product branch.
- Release 7.0.17 · OISF/suricata · GitHub →Original publisher ↗Searchable text snapshot · Captured 28 Sep 2026OISF / suricata Public Notifications You must be signed in to change notification settings Fork 1.8k Star 6.7k Code Pull requests 105 Actions Security and quality 86 Insights Additional navigation options Code Pull requests Actions Security and quality Insights 7.0.17 Compare Choose a tag to compare Sorr
- Release 8.0.6 · OISF/suricata · GitHub →Original publisher ↗Searchable text snapshot · Captured 28 Sep 2026OISF / suricata Public Notifications You must be signed in to change notification settings Fork 1.8k Star 6.7k Code Pull requests 105 Actions Security and quality 86 Insights Additional navigation options Code Pull requests Actions Security and quality Insights 8.0.6 Compare Choose a tag to compare Sorry
- flow: IPv4/IPv6 hash collision can reuse wrong flow state · Advisory · OISF/suricata · GitHub →Original publisher ↗Searchable text snapshot · Captured 28 Sep 2026OISF / suricata Public Notifications You must be signed in to change notification settings Fork 1.8k Star 6.7k Code Pull requests 105 Actions Security and quality 86 Insights Additional navigation options Code Pull requests Actions Security and quality Insights flow: IPv4/IPv6 hash collision can reuse wro
04
Evidence and provenance
Published 18 Sept 2026 · Last source change 25 Sept 2026, 19:22 UTC · CWE-697 · Incorrect Comparison
CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source FIRST · tracked since 2026-09-19
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2026-83398
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD enriched
Core structured fields are present and their contributing authorities are shown above.
Material change intelligence
View recent updates ↗What changed after publication
- Vendor guidanceAuthoritative vendor guidance changed: added patch: github.com/181b3b2fdd1fe87e4534de4fc79e29a083ef125f; added patch: github.com/4e2f23d031fbcfd72883bacd3d723c9874f23701; 3 further additions.security-advisories@github.com ↗
- Before
- no authoritative guidance recorded
- After
- patch: github.com/181b3b2fdd1fe87e4534de4fc79e29a083ef125f · patch: github.com/4e2f23d031fbcfd72883bacd3d723c9874f23701 · patch: github.com/bc41dcc854e24487d3786ce578a8a86a8350ab20 · 2 more references
- Affected versionsThe structured affected or fixed version information changed.CNA ↗
- Before
- suricata: >= 8.0.0, < 8.0.6, < 7.0.17 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
- After
- suricata: >= 8.0.0, < 8.0.6, < 7.0.17 · Fixed: An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
- Remediation statusRemediation status changed from Awaiting fix to Patch available.security-advisories@github.com ↗
- Before
- Awaiting fix
- After
- Patch available
- ENISA EUVD mappingEUVD-2026-83398 was added to the official ENISA EUVD mapping for this CVE.ENISA EUVD ↗
- Before
- not recorded
- After
- {"euvdId":"EUVD-2026-83398"}
- Catalogue recordCVE added to the BlackTree catalogue.CNA ↗
CVE published
Fixed release or patch reference recorded
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.