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CVE-2026-63446

Suricata app-layer: passed flows can retain transactions, causing resource exhaustion

7.5 HighFix available

Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. From 8.0.0 until 8.0.6, AppLayerParserSetTransactionInspectId() in src/app-layer-parser.c uses an inverted guard and marks only already-inspected transactions as inspected. On flows passed by a pass rule or pass-the-flow exception policy, detection is skipped, so completed transactions remain unmarked, are never freed, and are repeatedly rescanned. The per-flow list can grow without bound with quadratic cleanup cost, causing CPU and memory exhaustion. This issue is fixed in version 8.0.6.

Attack profile

How easy it is to exploit

Attack vector
Network
Complexity
Low
Privileges needed
None
User interaction
None

What an attacker can affect

Confidentiality
None
Integrity
None
Availability
High

Exploit likelihood

0.68%Up 0.3 points since Sep 19, 2026
90%50%10%1%

What each source reports

CVE List Score used 7.5

Suricata app-layer: passed flows can retain transactions, causing resource exhaustion

Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. From 8.0.0 until 8.0.6, AppLayerParserSetTransactionInspectId() in src/app-layer-parser.c uses an inverted guard and marks only already-inspected transactions as inspected. On flows passed by a pass rule or pass-the-flow exception policy, detection is skipped, so completed transactions remain unmarked, are never freed, and are repeatedly rescanned. The per-flow list can grow without bound with quadratic cleanup cost, causing CPU and memory exhaustion. This issue is fixed in version 8.0.6.

Record
CVE-2026-63446
CVSS 3.1
7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness
CWE-401, CWE-407
Updated
2026-11-02
EUVDEUVD-2026-83395 7.5

Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. From 8.0.0 until 8.0.6, AppLayerParserSetTransactionInspectId() in src/app-layer-parser.c uses an inverted guard and marks only already-inspected transactions as inspected. On flows passed by a pass rule or pass-the-flow exception policy, detection is skipped, so completed transactions remain unmarked, are never freed, and are repeatedly rescanned. The per-flow list can grow without bound with quadratic cleanup cost, causing CPU and memory exhaustion. This issue is fixed in version 8.0.6.

Record
EUVD-2026-83395
CVSS 3.1
7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated
2026-11-02
NVD 7.5

Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. From 8.0.0 until 8.0.6, AppLayerParserSetTransactionInspectId() in src/app-layer-parser.c uses an inverted guard and marks only already-inspected transactions as inspected. On flows passed by a pass rule or pass-the-flow exception policy, detection is skipped, so completed transactions remain unmarked, are never freed, and are repeatedly rescanned. The per-flow list can grow without bound with quadratic cleanup cost, causing CPU and memory exhaustion. This issue is fixed in version 8.0.6.

Record
CVE-2026-63446
CVSS 3.1
7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness
CWE-401, CWE-407
Updated
2026-11-02
OSV 7.5

Suricata app-layer: passed flows can retain transactions, causing resource exhaustion

Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. From 8.0.0 until 8.0.6, AppLayerParserSetTransactionInspectId() in src/app-layer-parser.c uses an inverted guard and marks only already-inspected transactions as inspected. On flows passed by a pass rule or pass-the-flow exception policy, detection is skipped, so completed transactions remain unmarked, are never freed, and are repeatedly rescanned. The per-flow list can grow without bound with quadratic cleanup cost, causing CPU and memory exhaustion. This issue is fixed in version 8.0.6.

Record
CVE-2026-63446
CVSS 3.1
7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness
CWE-401, CWE-407
Updated
2026-11-02
OSVDEBIAN-CVE-2026-63446 7.5

Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. From 8.0.0 until 8.0.6, AppLayerParserSetTransactionInspectId() in src/app-layer-parser.c uses an inverted guard and marks only already-inspected transactions as inspected. On flows passed by a pass rule or pass-the-flow exception policy, detection is skipped, so completed transactions remain unmarked, are never freed, and are repeatedly rescanned. The per-flow list can grow without bound with quadratic cleanup cost, causing CPU and memory exhaustion. This issue is fixed in version 8.0.6.

Record
DEBIAN-CVE-2026-63446
CVSS 3.1
7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated
2026-11-02
OSVUBUNTU-CVE-2026-63446 7.5

Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. From 8.0.0 until 8.0.6, AppLayerParserSetTransactionInspectId() in src/app-layer-parser.c uses an inverted guard and marks only already-inspected transactions as inspected. On flows passed by a pass rule or pass-the-flow exception policy, detection is skipped, so completed transactions remain unmarked, are never freed, and are repeatedly rescanned. The per-flow list can grow without bound with quadratic cleanup cost, causing CPU and memory exhaustion. This issue is fixed in version 8.0.6.

Record
UBUNTU-CVE-2026-63446
CVSS 3.1
7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated
2026-11-02

Affected products

Affected packages

Affected packages
PackageAffectedFixed
suricata
Debian:13
All versions, plus listed versions
1:7.0.10-11:7.0.10-1+deb13u11:7.0.10-1+deb13u21:7.0.10-1+deb13u31:7.0.10-1+deb13u4
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1:7.0.11-11:7.0.11-1~bpo13+11:8.0.0-1~exp11:8.0.0-1~exp21:8.0.0-1~exp41:8.0.0-1~exp51:8.0.1-11:8.0.1-21:8.0.1-31:8.0.1-3~bpo13+11:8.0.2-11:8.0.2-1~bpo13+11:8.0.3-11:8.0.3-1~bpo13+11:8.0.3-2~exp11:8.0.4-11:8.0.4-1~bpo13+11:8.0.5-11:8.0.5-1~bpo13+11:8.0.6-11:8.0.6-1~bpo13+11:8.0.7-11:8.0.7-1~bpo13+11:8.0.7-2~exp1
None known
suricata
Debian:14
before 1:8.0.6-1, plus listed versions
1:7.0.10-11:7.0.11-11:7.0.11-1~bpo13+11:8.0.0-1~exp11:8.0.0-1~exp2
Show 16 moreShow less
1:8.0.0-1~exp41:8.0.0-1~exp51:8.0.1-11:8.0.1-21:8.0.1-31:8.0.1-3~bpo13+11:8.0.2-11:8.0.2-1~bpo13+11:8.0.3-11:8.0.3-1~bpo13+11:8.0.3-2~exp11:8.0.4-11:8.0.4-1~bpo13+11:8.0.5-11:8.0.5-1~bpo13+11:8.0.6-1~bpo13+1
1:8.0.6-1
suricata
Ubuntu:16.04:LTS
All versions, plus listed versions
2.0.8-1build12.0.9-12.0.10-12.0.10-22.0.11-13.0-1
None known
suricata
Ubuntu:18.04:LTS
All versions, plus listed versions
3.2-2ubuntu3
None known
suricata
Ubuntu:22.04:LTS
All versions, plus listed versions
1:6.0.4-21:6.0.4-3
None known
suricata
Ubuntu:24.04:LTS
All versions, plus listed versions
1:7.0.0-21:7.0.2-11:7.0.2-1build11:7.0.3-1build11:7.0.3-1build3
None known
suricata
Ubuntu:26.04:LTS
All versions, plus listed versions
1:7.0.10-11:8.0.1-3build11:8.0.2-11:8.0.2-1build11:8.0.3-1
None known

History

History
RecordedChangedSources
first indexedCVE List, EUVD, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-63446 is a high vulnerability (CVSS 7.5) in Oisf Suricata, published September 18, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.68%, the 52nd percentile. Fixed in suricata 1:8.0.6-1.

References

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