Every CVE Search/ Get API key

CVE-2026-123125

Symfony: Ip Constraint public/private Modes Accept IPv4-Mapped and IPv4-Compatible IPv6 Addresses allowing SSRF Filter Bypass

6.3 MediumFix available

The Symfony Validator component IpValidator incompletely classifies internal addresses in the filtered modes of the Ip constraint, so some internal addresses are accepted as public, which can lead to Server-Side Request Forgery (SSRF) in Symfony versions prior to 5.4.56, 6.x prior to 6.4.50, 7.x prior to 7.4.23, and 8.x prior to 8.1.11.

In these modes, IpValidator relies on the PHP flags FILTER_FLAG_NO_PRIV_RANGE and FILTER_FLAG_NO_RES_RANGE to classify addresses as public, private, or reserved. These flags do not cover shared address space (100.64.0.0/10) or IPv4-mapped, IPv4-compatible, and 6to4 IPv6 addresses, which can embed internal IPv4 addresses. A value such as ::ffff:127.0.0.1 can therefore pass validation even though it points to an internal host. Applications that rely on the Ip constraint to reject internal addresses, for example before making a server-side request to a user-supplied address, can be exposed to SSRF.

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
None

Exploit likelihood

0.21%Unchanged since Nov 6, 2026
90%50%10%1%

What each source reports

CVE List Score used 6.3

Symfony: Ip Constraint public/private Modes Accept IPv4-Mapped and IPv4-Compatible IPv6 Addresses allowing SSRF Filter Bypass

The Symfony Validator component IpValidator incompletely classifies internal addresses in the filtered modes of the Ip constraint, so some internal addresses are accepted as public, which can lead to Server-Side Request Forgery (SSRF) in Symfony versions prior to 5.4.56, 6.x prior to 6.4.50, 7.x prior to 7.4.23, and 8.x prior to 8.1.11.

In these modes, IpValidator relies on the PHP flags FILTER_FLAG_NO_PRIV_RANGE and FILTER_FLAG_NO_RES_RANGE to classify addresses as public, private, or reserved. These flags do not cover shared address space (100.64.0.0/10) or IPv4-mapped, IPv4-compatible, and 6to4 IPv6 addresses, which can embed internal IPv4 addresses. A value such as ::ffff:127.0.0.1 can therefore pass validation even though it points to an internal host. Applications that rely on the Ip constraint to reject internal addresses, for example before making a server-side request to a user-supplied address, can be exposed to SSRF.

Record
CVE-2026-123125
CVSS 4.0
6.3 MediumCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
CVSS 3.1
6.5 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Weakness
CWE-184, CWE-918
Updated
2026-11-05
EUVDEUVD-2026-117557 6.3

The Symfony Validator component IpValidator incompletely classifies internal addresses in the filtered modes of the Ip constraint, so some internal addresses are accepted as public, which can lead to Server-Side Request Forgery (SSRF) in Symfony versions prior to 5.4.56, 6.x prior to 6.4.50, 7.x prior to 7.4.23, and 8.x prior to 8.1.11.

In these modes, IpValidator relies on the PHP flags FILTER_FLAG_NO_PRIV_RANGE and FILTER_FLAG_NO_RES_RANGE to classify addresses as public, private, or reserved. These flags do not cover shared address space (100.64.0.0/10) or IPv4-mapped, IPv4-compatible, and 6to4 IPv6 addresses, which can embed internal IPv4 addresses. A value such as ::ffff:127.0.0.1 can therefore pass validation even though it points to an internal host. Applications that rely on the Ip constraint to reject internal addresses, for example before making a server-side request to a user-supplied address, can be exposed to SSRF.

Record
EUVD-2026-117557
CVSS 4.0
6.3 MediumCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
Updated
2026-11-05
NVD 6.3

The Symfony Validator component IpValidator incompletely classifies internal addresses in the filtered modes of the Ip constraint, so some internal addresses are accepted as public, which can lead to Server-Side Request Forgery (SSRF) in Symfony versions prior to 5.4.56, 6.x prior to 6.4.50, 7.x prior to 7.4.23, and 8.x prior to 8.1.11.

In these modes, IpValidator relies on the PHP flags FILTER_FLAG_NO_PRIV_RANGE and FILTER_FLAG_NO_RES_RANGE to classify addresses as public, private, or reserved. These flags do not cover shared address space (100.64.0.0/10) or IPv4-mapped, IPv4-compatible, and 6to4 IPv6 addresses, which can embed internal IPv4 addresses. A value such as ::ffff:127.0.0.1 can therefore pass validation even though it points to an internal host. Applications that rely on the Ip constraint to reject internal addresses, for example before making a server-side request to a user-supplied address, can be exposed to SSRF.

Record
CVE-2026-123125
CVSS 4.0
6.3 MediumCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/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
CVSS 3.1
6.5 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Weakness
CWE-184, CWE-918
Updated
2026-11-07
OSV 6.3

Symfony: Ip Constraint public/private Modes Accept IPv4-Mapped and IPv4-Compatible IPv6 Addresses allowing SSRF Filter Bypass

The Symfony Validator component IpValidator incompletely classifies internal addresses in the filtered modes of the Ip constraint, so some internal addresses are accepted as public, which can lead to Server-Side Request Forgery (SSRF) in Symfony versions prior to 5.4.56, 6.x prior to 6.4.50, 7.x prior to 7.4.23, and 8.x prior to 8.1.11.

In these modes, IpValidator relies on the PHP flags FILTER_FLAG_NO_PRIV_RANGE and FILTER_FLAG_NO_RES_RANGE to classify addresses as public, private, or reserved. These flags do not cover shared address space (100.64.0.0/10) or IPv4-mapped, IPv4-compatible, and 6to4 IPv6 addresses, which can embed internal IPv4 addresses. A value such as ::ffff:127.0.0.1 can therefore pass validation even though it points to an internal host. Applications that rely on the Ip constraint to reject internal addresses, for example before making a server-side request to a user-supplied address, can be exposed to SSRF.

Record
CVE-2026-123125
CVSS 4.0
6.3 MediumCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
Weakness
CWE-184, CWE-918
Updated
2026-11-07
OSVDEBIAN-CVE-2026-123125 6.3

The Symfony Validator component IpValidator incompletely classifies internal addresses in the filtered modes of the Ip constraint, so some internal addresses are accepted as public, which can lead to Server-Side Request Forgery (SSRF) in Symfony versions prior to 5.4.56, 6.x prior to 6.4.50, 7.x prior to 7.4.23, and 8.x prior to 8.1.11. In these modes, IpValidator relies on the PHP flags FILTER_FLAG_NO_PRIV_RANGE and FILTER_FLAG_NO_RES_RANGE to classify addresses as public, private, or reserved. These flags do not cover shared address space (100.64.0.0/10) or IPv4-mapped, IPv4-compatible, and 6to4 IPv6 addresses, which can embed internal IPv4 addresses. A value such as ::ffff:127.0.0.1 can therefore pass validation even though it points to an internal host. Applications that rely on the Ip constraint to reject internal addresses, for example before making a server-side request to a user-supplied address, can be exposed to SSRF.

Record
DEBIAN-CVE-2026-123125
CVSS 4.0
6.3 MediumCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/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
Updated
2026-11-07
OSVUBUNTU-CVE-2026-123125 6.3

The Symfony Validator component IpValidator incompletely classifies internal addresses in the filtered modes of the Ip constraint, so some internal addresses are accepted as public, which can lead to Server-Side Request Forgery (SSRF) in Symfony versions prior to 5.4.56, 6.x prior to 6.4.50, 7.x prior to 7.4.23, and 8.x prior to 8.1.11. In these modes, IpValidator relies on the PHP flags FILTER_FLAG_NO_PRIV_RANGE and FILTER_FLAG_NO_RES_RANGE to classify addresses as public, private, or reserved. These flags do not cover shared address space (100.64.0.0/10) or IPv4-mapped, IPv4-compatible, and 6to4 IPv6 addresses, which can embed internal IPv4 addresses. A value such as ::ffff:127.0.0.1 can therefore pass validation even though it points to an internal host. Applications that rely on the Ip constraint to reject internal addresses, for example before making a server-side request to a user-supplied address, can be exposed to SSRF.

Record
UBUNTU-CVE-2026-123125
CVSS 4.0
6.3 MediumCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
CVSS 3.1
6.5 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Updated
2026-11-07

Affected products

Affected packages

Affected packages
PackageAffectedFixed
symfony
Debian:12
All versions, plus listed versions
5.4.23+dfsg-15.4.23+dfsg-1+deb12u15.4.23+dfsg-1+deb12u25.4.23+dfsg-1+deb12u35.4.23+dfsg-1+deb12u4
Show 45 moreShow less
5.4.23+dfsg-1+deb12u55.4.24+dfsg-15.4.25+dfsg-15.4.27+dfsg-15.4.28+dfsg-15.4.29+dfsg-15.4.30+dfsg-15.4.31+dfsg-15.4.31+dfsg-25.4.32+dfsg-15.4.33+dfsg-15.4.34+dfsg-15.4.34+dfsg-25.4.35+dfsg-15.4.35+dfsg-25.4.35+dfsg-35.4.52+dfsg-0+deb12u15.4.53+dfsg-0+deb12u16.3.0+dfsg-16.3.0~rc1+dfsg-16.3.0~rc2+dfsg-16.3.1+dfsg-16.3.3+dfsg-16.3.4+dfsg-16.3.5+dfsg-16.3.6+dfsg-16.3.7+dfsg-16.4.0+dfsg-16.4.0~beta2+dfsg-16.4.0~beta3+dfsg-16.4.0~rc1+dfsg-16.4.0~rc2+dfsg-16.4.1+dfsg-16.4.10+dfsg-16.4.11+dfsg-16.4.12+dfsg-16.4.13+dfsg-16.4.14+dfsg-16.4.15+dfsg-16.4.16+dfsg-16.4.16+dfsg-26.4.17+dfsg-16.4.17+dfsg-26.4.17+dfsg-36.4.17+dfsg-4
None known
symfony
Debian:13
All versions, plus listed versions
6.4.21+dfsg-26.4.21+dfsg-2+deb13u16.4.24+dfsg-16.4.25+dfsg-16.4.40+dfsg-0+deb13u1
Show 45 moreShow less
6.4.41+dfsg-0+deb13u16.4.49+dfsg-0+deb13u17.0.4+dfsg-17.0.5+dfsg-17.0.6+dfsg-17.0.7+dfsg-17.1.0~beta1+dfsg-17.1.0~rc1+dfsg-17.1.2+dfsg-17.1.3+dfsg-17.1.4+dfsg-17.1.5+dfsg-17.2.0~beta1+dfsg-17.2.0~beta2+dfsg-17.2.0~rc1+dfsg-17.2.1+dfsg-17.2.2+dfsg-17.2.3+dfsg-17.2.4+dfsg-17.2.5+dfsg-17.2.6-17.3.0+dfsg-17.3.0~beta1+dfsg-17.3.0~beta2+dfsg-17.3.0~rc1+dfsg-17.3.1+dfsg-17.3.2+dfsg-17.3.3+dfsg-17.3.4+dfsg-17.3.5-17.4.0+dfsg-17.4.0+dfsg-27.4.0~beta1-17.4.0~beta1-27.4.0~beta2+dfsg-17.4.0~beta2+dfsg-27.4.0~beta2+dfsg-37.4.0~rc1+dfsg-17.4.0~rc2+dfsg-17.4.0~rc3+dfsg-17.4.10+dfsg-17.4.12+dfsg-17.4.13+dfsg-17.4.13+dfsg-27.4.14+dfsg-1
None known
symfony
Debian:14
before 7.4.23+dfsg-1, plus listed versions
6.4.21+dfsg-26.4.24+dfsg-16.4.25+dfsg-17.0.4+dfsg-17.0.5+dfsg-1
Show 45 moreShow less
7.0.6+dfsg-17.0.7+dfsg-17.1.0~beta1+dfsg-17.1.0~rc1+dfsg-17.1.2+dfsg-17.1.3+dfsg-17.1.4+dfsg-17.1.5+dfsg-17.2.0~beta1+dfsg-17.2.0~beta2+dfsg-17.2.0~rc1+dfsg-17.2.1+dfsg-17.2.2+dfsg-17.2.3+dfsg-17.2.4+dfsg-17.2.5+dfsg-17.2.6-17.3.0+dfsg-17.3.0~beta1+dfsg-17.3.0~beta2+dfsg-17.3.0~rc1+dfsg-17.3.1+dfsg-17.3.2+dfsg-17.3.3+dfsg-17.3.4+dfsg-17.3.5-17.4.0+dfsg-17.4.0+dfsg-27.4.0~beta1-17.4.0~beta1-27.4.0~beta2+dfsg-17.4.0~beta2+dfsg-27.4.0~beta2+dfsg-37.4.0~rc1+dfsg-17.4.0~rc2+dfsg-17.4.0~rc3+dfsg-17.4.10+dfsg-17.4.12+dfsg-17.4.13+dfsg-17.4.13+dfsg-27.4.14+dfsg-17.4.15+dfsg-17.4.15+dfsg-27.4.16+dfsg-17.4.17+dfsg-1
7.4.23+dfsg-1
symfony
Ubuntu:16.04:LTS
All versions, plus listed versions
2.7.1+dfsg-12.7.5+dfsg-12.7.9+dfsg-12.7.9+dfsg-1ubuntu22.7.10-0ubuntu2
None known
symfony
Ubuntu:Pro:18.04:LTS
All versions, plus listed versions
2.8.7+dfsg-1.3ubuntu13.4.3+dfsg-1ubuntu43.4.6+dfsg-13.4.6+dfsg-1ubuntu0.13.4.6+dfsg-1ubuntu0.1+esm13.4.6+dfsg-1ubuntu0.1+esm2
None known
symfony
Ubuntu:Pro:20.04:LTS
All versions, plus listed versions
4.3.4+dfsg-1ubuntu14.3.8+dfsg-1ubuntu14.3.8+dfsg-1ubuntu1+esm14.3.8+dfsg-1ubuntu1+esm2
None known
symfony
Ubuntu:Pro:22.04:LTS
All versions, plus listed versions
5.2.6+dfsg-1ubuntu75.4.4+dfsg-1ubuntu85.4.4+dfsg-1ubuntu8+esm1
None known
symfony
Ubuntu:Pro:24.04:LTS
All versions, plus listed versions
5.4.23+dfsg-1ubuntu15.4.35+dfsg-3ubuntu16.4.5+dfsg-3ubuntu26.4.5+dfsg-3ubuntu36.4.5+dfsg-3ubuntu3+esm1
None known
symfony
Ubuntu:26.10
All versions, plus listed versions
7.4.7+dfsg-1ubuntu17.4.9+dfsg-1ubuntu17.4.13+dfsg-2ubuntu17.4.14+dfsg-1ubuntu27.4.15+dfsg-2ubuntu27.4.16+dfsg-1ubuntu2
None known
symfony
Ubuntu:26.04:LTS
All versions, plus listed versions
6.4.24+dfsg-17.4.5+dfsg-1ubuntu17.4.6+dfsg-2ubuntu17.4.7+dfsg-1ubuntu1
None known

History

History
RecordedChangedSources
affected, factsOSV
referencesOSV
affected, aliases, referencesNVD, OSV
affected, aliases, referencesOSV
aliases, referencesCVE List, NVD, OSV
aliases, products, publishedEUVD
first indexedCVE List

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

In short

CVE-2026-123125 is a medium vulnerability (CVSS 6.3) in Sensiolabs Symfony, published November 5, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.21%, the 10th percentile. Fixed in symfony 7.4.23+dfsg-1.

References

This page doesn't list everything

Left out here: 183 versions. The JSON record has them.

MoveEnter Open