Azure Linux 3.0 Security Update: CBL-Mariner Releases (CVE-2026-39821)

The version of CBL-Mariner Releases installed on the remote Azure Linux 3.0 host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the CVE-2026-39821 advisory. - The ToASCII and ToUnicode functions incorrectly accept Punycode-encoded labels that decode to ...

symfony/polyfill-intl-idn: xn-- labels with ASCII-only Punycode payloads are treated as equivalent to their decoded form

Description symfony/polyfill-intl-idn provides a userland implementation of idntoutf8 and idntoascii for runtimes that lack the intl extension. Its Idn::process method decodes labels prefixed with xn-- using Punycode but never enforces the validity criterion added in UTS 46 revision 33 Section 4...

GHSA-2XF4-CG6J-VHGQ symfony/polyfill-intl-idn: xn-- labels with ASCII-only Punycode payloads are treated as equivalent to their decoded form

Description symfony/polyfill-intl-idn provides a userland implementation of idntoutf8 and idntoascii for runtimes that lack the intl extension. Its Idn::process method decodes labels prefixed with xn-- using Punycode but never enforces the validity criterion added in UTS 46 revision 33 Section 4...

SUSE CVE-2026-39821

The ToASCII and ToUnicode functions incorrectly accept Punycode-encoded labels that decode to an ASCII-only label. For example, ToUnicode"xn--example-.com" incorrectly returns the name "example.com" rather than an error. This behavior can lead to privilege escalation in programs using the idna...

Invoking failure to reject ASCII-only Punycode-encoded labels in golang.org/x/net/idna

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Linux Distros Unpatched Vulnerability : CVE-2026-39821

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - The ToASCII and ToUnicode functions incorrectly accept Punycode-encoded labels that decode to an ASCII- only label. For example, ToUnicodexn--example-.com...

Incorrect Comparison

Overview Affected versions of this package are vulnerable to Incorrect Comparison in the process function in Idn.php, which does not necessarily treat xn-- labeled input as punycode, if it contains only ASCII. This case was overlooked in the specification until UTS 46 revision 33, when it was...

CVE-2026-46644: symfony/polyfill-intl-idn accepts xn-- labels whose Punycode payload decodes to ASCII-only: insecure equivalence

More info at https://symfony.com/cve-2026-46644...

CVE-2026-46644: symfony/polyfill-intl-idn accepts xn-- labels whose Punycode payload decodes to ASCII-only: insecure equivalence

More info at https://symfony.com/cve-2026-46644...

Improper Authentication

Overview Affected versions of this package are vulnerable to Improper Authentication via the ToASCII and ToUnicode functions. An attacker can bypass hostname validation by submitting Punycode-encoded labels that decode to ASCII-only labels, potentially leading to privilege escalation in...

Improper Authentication

Overview Affected versions of this package are vulnerable to Improper Authentication via the ToASCII and ToUnicode functions. An attacker can bypass hostname validation by submitting Punycode-encoded labels that decode to ASCII-only labels, potentially leading to privilege escalation in...

DEBIAN-CVE-2026-39821

The ToASCII and ToUnicode functions incorrectly accept Punycode-encoded labels that decode to an ASCII-only label. For example, ToUnicode"xn--example-.com" incorrectly returns the name "example.com" rather than an error. This behavior can lead to privilege escalation in programs using the idna...

CVE-2026-39821

The ToASCII and ToUnicode functions incorrectly accept Punycode-encoded labels that decode to an ASCII-only label. For example, ToUnicode"xn--example-.com" incorrectly returns the name "example.com" rather than an error. This behavior can lead to privilege escalation in programs using the idna...

UBUNTU-CVE-2026-39821

The ToASCII and ToUnicode functions incorrectly accept Punycode-encoded labels that decode to an ASCII-only label. For example, ToUnicode"xn--example-.com" incorrectly returns the name "example.com" rather than an error. This behavior can lead to privilege escalation in programs using the idna...

CVE-2026-39821

The ToASCII and ToUnicode functions incorrectly accept Punycode-encoded labels that decode to an ASCII-only label. For example, ToUnicode"xn--example-.com" incorrectly returns the name "example.com" rather than an error. This behavior can lead to privilege escalation in programs using the idna...

CVE-2026-39821

The ToASCII and ToUnicode functions incorrectly accept Punycode-encoded labels that decode to an ASCII-only label. For example, ToUnicode"xn--example-.com" incorrectly returns the name "example.com" rather than an error. This behavior can lead to privilege escalation in programs using the idna...

EUVD-2026-31449

The ToASCII and ToUnicode functions incorrectly accept Punycode-encoded labels that decode to an ASCII-only label. For example, ToUnicode"xn--example-.com" incorrectly returns the name "example.com" rather than an error. This behavior can lead to privilege escalation in programs using the idna...

CVE-2026-39821 Invoking failure to reject ASCII-only Punycode-encoded labels in golang.org/x/net/idna

The ToASCII and ToUnicode functions incorrectly accept Punycode-encoded labels that decode to an ASCII-only label. For example, ToUnicode"xn--example-.com" incorrectly returns the name "example.com" rather than an error. This behavior can lead to privilege escalation in programs using the idna...

CVE-2026-39821

The ToASCII and ToUnicode functions incorrectly accept Punycode-encoded labels that decode to an ASCII-only label. For example, ToUnicode"xn--example-.com" incorrectly returns the name "example.com" rather than an error. This behavior can lead to privilege escalation in programs using the idna...

CVE-2026-39821

CVE-2026-39821 affects golang.org/x/net/idna; ToASCII/ToUnicode incorrectly accept Punycode-encoded labels that decode to ASCII-only labels (e.g., xn--example-.com). The issue can enable privilege escalation in programs that validate ASCII hostnames but later convert to Unicode, potentially grant...