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CVE-2026-25075· NVD / CVE Program· CNA VulnCheck

strongSwan 4.5.0 < 6.0.5 EAP-TTLS AVP Parsing Integer Underflow

Noroxi assessment

Priority: Monitor (action score 34/100)

  • Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
  • Probability of exploitation in the next 30 days: 1% (FIRST EPSS); higher than 64% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: strongSwan strongSwan 6.0.5; azl3 strongswan 5.9.14-8 on Azure Linux 3.0 5.9.14-9.

Low priority for now. Upgrade to strongSwan strongSwan 6.0.5; azl3 strongswan 5.9.14-8 on Azure Linux 3.0 5.9.14-9 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

strongSwan versions 4.5.0 prior to 6.0.5 contain an integer underflow vulnerability in the EAP-TTLS AVP parser that allows unauthenticated remote attackers to cause a denial of service by sending crafted AVP data with invalid length fields during IKEv2 authentication. Attackers can exploit the failure to validate AVP length fields before subtraction to trigger excessive memory allocation or NULL pointer dereference, crashing the charon IKE daemon.

HighCVSS 8.7 · v4.0—Proof of concept Fix available
Published
Mar 23, 2026
Updated
Jul 14, 2026
EPSS
1.0% · 64th percentile

Report tools

JSON

Action score

34

Monitor

Low priority for now.

CVSS
34 / 40 · 8.7 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 1.0%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · VulnCheck
8.7
NVD has not scored this yet; the score shown is the CNA’s.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • Proof of concept exists, no weaponized module
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-25075

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (VulnCheck). Independent of NVD's CPE analysis and usually ahead of it.

  • strongSwan strongSwan

    • 4.5.0 and later · before 6.0.5affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:11strongswanbefore 5.9.1-1+deb11u65.9.1-1+deb11u6
Debian:12strongswanbefore 5.9.8-5+deb12u35.9.8-5+deb12u3
Debian:13strongswanbefore 6.0.1-6+deb13u46.0.1-6+deb13u4
Debian:14strongswanbefore 6.0.5-16.0.5-1
openSUSE:Leap 15.6strongswanbefore 5.9.12-150600.3.11.15.9.12-150600.3.11.1
openSUSE:Leap 16.0strongswanbefore 6.0.4-160000.1.16.0.4-160000.1.1
openSUSE:Tumbleweedstrongswanbefore 6.0.5-1.16.0.5-1.1
SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOSstrongswanbefore 5.9.11-150400.19.26.15.9.11-150400.19.26.1
SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOSstrongswanbefore 5.9.11-150500.5.14.15.9.11-150500.5.14.1
SUSE:Linux Enterprise Module for Basesystem 15 SP7strongswanbefore 5.9.14-150700.3.9.15.9.14-150700.3.9.1
SUSE:Linux Enterprise Server 12 SP5-LTSSstrongswanbefore 5.1.3-26.32.15.1.3-26.32.1
SUSE:Linux Enterprise Server 15 SP6-LTSSstrongswanbefore 5.9.12-150600.3.11.15.9.12-150600.3.11.1
SUSE:Linux Enterprise Server 16.0strongswanbefore 6.0.4-160000.1.16.0.4-160000.1.1

Same product

strongswan: all records

Other highest-scoring records for the same primary product.

  • CVE-2023-41913strongSwan before 5.9.12 has a buffer overflow and possible unauthenticated remote code execution via a DH public value that exceeds the int
    40Plan
  • CVE-2023-26463strongSwan 5.9.8 and 5.9.9 potentially allows remote code execution because it uses a variable named "public" for two different purposes wit
    40Plan
  • CVE-2015-3991strongSwan 5.2.2 and 5.3.0 allows remote attackers to cause a denial of service (daemon crash) or execute arbitrary code.
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2022-4967May 14, 2024 · strongSwan versions 5.9.2 through 5.9.5 are affected by authorization bypass through improper validation of certificate with host mismatch (
    26Monitor
  • ← EarlierCVE-2025-62291Jan 16, 2026 · In the eap-mschapv2 plugin (client-side) in strongSwan before 6.0.3, a malicious EAP-MSCHAPv2 server can send a crafted message of size 6 th
    32Monitor
  • Later →CVE-2026-47895Aug 22, 2026 · In strongSwan before 6.0.7, identity parsing/cloning is mishandled.
    30Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
strongSwan strongSwan6.0.5Vendor (CNA)
azl3 strongswan 5.9.14-8 on Azure Linux 3.05.9.14-9 · CBL-Mariner ReleasesMicrosoft (MSRC)
debian:strongswan5.9.8-5+deb12u3 · Debian:12Package registry (OSV)
opensuse:strongswan5.9.12-150600.3.11.1 · openSUSE:Leap 15.6Package registry (OSV)
suse:strongswan5.9.11-150500.5.14.1 · SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOSPackage registry (OSV)
suse:strongswan5.9.12-150600.3.11.1 · SUSE:Linux Enterprise Server 15 SP6-LTSSPackage registry (OSV)

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

  • Proof-of-concept repository on GitHub ×1

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Proof-of-concept repository on GitHubstars:22026-03-26

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. Published
  2. First PoC+2 d
  3. TodayOct 25, 2026+216 d
EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2025-6229166 days apartIn the eap-mschapv2 plugin (client-side) in strongSwan before 6.0.3, a malicious EAP-MSCHAPv2 server can send a crafted message of size 6 th
    32Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
Integrity
Availability
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
X

Weakness class (CWE)

CWE-191 · Integer Underflow (Wrap or Wraparound)

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (4 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records