UBUNTU-CVE-2026-5503

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Source

https://ubuntu.com/security/CVE-2026-5503

Import Source

https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-5503.json

JSON Data

https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-5503

Upstream

CVE-2026-5503

Published

2026-04-09T23:17:00Z

Modified

2026-05-26T19:29:37.220091783Z

Severity

6.9 (Medium) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N CVSS Calculator
9.1 (Critical) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H CVSS Calculator
Ubuntu - medium

Summary

[none]

Details

In TLSXEchChangeSNI, the ctx->extensions branch set extensions unconditionally even when TLSXFind returned NULL. This caused TLSXUseSNI to attach the attacker-controlled publicName to the shared WOLFSSLCTX when no inner SNI was configured. TLSXEchRestoreSNI then failed to clean it up because its removal was gated on serverNameX != NULL. The inner ClientHello was sized before the pollution but written after it, causing TLSXSNI_Write to memcpy 255 bytes past the allocation boundary.

References

Affected packages

Ubuntu:16.04:LTS

wolfssl

Package

Name: wolfssl
Purl: pkg:deb/ubuntu/wolfssl?arch=source&distro=xenial

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Affected versions

3.*

3.4.8+dfsg-1

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "libcyassl5",
            "binary_version": "3.4.8+dfsg-1"
        },
        {
            "binary_name": "libwolfssl0",
            "binary_version": "3.4.8+dfsg-1"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-5503.json"

Ubuntu:18.04:LTS

wolfssl

Package

Name: wolfssl
Purl: pkg:deb/ubuntu/wolfssl?arch=source&distro=bionic

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Affected versions

3.*

3.10.2+dfsg-2

3.12.0+dfsg-1

3.12.2+dfsg-1

3.13.0+dfsg-1

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "libwolfssl15",
            "binary_version": "3.13.0+dfsg-1"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-5503.json"

Ubuntu:20.04:LTS

wolfssl

Package

Name: wolfssl
Purl: pkg:deb/ubuntu/wolfssl?arch=source&distro=focal

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Affected versions

4.*

4.1.0+dfsg-2

4.2.0+dfsg-1

4.2.0+dfsg-2

4.2.0+dfsg-3

4.3.0+dfsg-2

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "libwolfssl24",
            "binary_version": "4.3.0+dfsg-2"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-5503.json"

Ubuntu:22.04:LTS

wolfssl

Package

Name: wolfssl
Purl: pkg:deb/ubuntu/wolfssl?arch=source&distro=jammy

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Affected versions

4.*

4.6.0-3

5.*

5.0.0-1

5.1.1-1

5.2.0-1

5.2.0-2

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "libwolfssl32",
            "binary_version": "5.2.0-2"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-5503.json"

Ubuntu:24.04:LTS

wolfssl

Package

Name: wolfssl
Purl: pkg:deb/ubuntu/wolfssl?arch=source&distro=noble

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Affected versions

5.*

5.5.4-2

5.5.4-2.1

5.6.4-2

5.6.6-1.2

5.6.6-1.3

5.6.6-1.3build1

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "libwolfssl42t64",
            "binary_version": "5.6.6-1.3build1"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-5503.json"

Ubuntu:25.10

wolfssl

Package

Name: wolfssl
Purl: pkg:deb/ubuntu/wolfssl?arch=source&distro=questing

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Affected versions

5.*

5.7.2-0.1

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "libwolfssl42t64",
            "binary_version": "5.7.2-0.1"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-5503.json"

Ubuntu:26.04:LTS

wolfssl

Package

Name: wolfssl
Purl: pkg:deb/ubuntu/wolfssl?arch=source&distro=resolute

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Affected versions

5.*

5.7.2-0.1

5.8.2-1.2

5.8.4-1

5.9.1-0.1

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "libwolfssl44",
            "binary_version": "5.9.1-0.1"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-5503.json"