### Description `Symfony\Component\HttpClient\NoPrivateNetworkHttpClient` is documented as a decorator that blocks requests to private networks by default. The list of blocked subnets (`Symfony\Component\HttpFoundation\IpUtils::PRIVATE_SUBNETS` on 6.4+, a private constant in `NoPrivateNetworkHttpClient` on 5.4) enumerates RFC1918, loopback, link-local and IPv4-mapped IPv6 (`::ffff:0:0/96`) prefixes, but omits the remaining IPv6 transition forms that can embed a private IPv4 destination: 6to4 (`2002::/16`, RFC 3056), Teredo (`2001::/32`, RFC 4380), NAT64 (`64:ff9b::/96`, RFC 6052 and `64:ff9b:1::/48`, RFC 8215) and IPv4-compatible IPv6 (`::/96`, RFC 4291 §2.5.5.1). `IpUtils::checkIp6()` is a pure bitwise CIDR comparison against the constants list and never extracts the embedded IPv4, so an attacker who can supply a URL writes the loopback / RFC1918 IPv4 target as e.g. `http://[2002:7f00:1::]/` (6to4 → 127.0.0.1), `http://[64:ff9b::7f00:1]/` (NAT64 → 127.0.0.1), `http://[::7f00:1]/` (IPv4-compatible → 127.0.0.1) or `http://[2001::1]/` (Teredo). `IpUtils::isPrivateIp()` returns `false` and `NoPrivateNetworkHttpClient` dispatches the request. Real-world reachability of the embedded IPv4 depends on the deploy's IPv6 routing (6to4 tunnel interface, upstream NAT64 gateway, kernel handling of IPv4-compatible addresses), but the security boundary the decorator promises — the dispatch decision — is crossed regardless of whether the packet ultimately lands on the embedded IPv4. ### Resolution The private-subnet list now includes `::/96`, `2002::/16`, `2001::/32`, `64:ff9b::/96` and `64:ff9b:1::/48`. Blanket blocking of these prefixes matches the policy applied by Chromium and Mozilla's Private Network Access; server-side HTTPS APIs are not legitimately published on these prefixes. The patches for this issue are available [here](https://github.com/symfony/symfony/commit/82765368cf74177c36613575182f168a2eb765b2) for branch 5.4 and [here](https://github.com/symfony/symfony/commit/85b831555be8ea1f43bf01078afe87bc4c92f65e) for branch 6.4 (and forward-ported to 7.4, 8.0 and 8.1). ### Credits Symfony would like to thank tonghuaroot for reporting the issue and Nicolas Grekas for providing the fix.
### Description `Symfony\Component\HttpClient\NoPrivateNetworkHttpClient` is documented as a decorator that blocks requests to private networks by default. The list of blocked subnets (`Symfony\Component\HttpFoundation\IpUtils::PRIVATE_SUBNETS` on 6.4+, a private constant in `NoPrivateNetworkHttpClient` on 5.4) enumerates RFC1918, loopback, link-local and IPv4-mapped IPv6 (`::ffff:0:0/96`) prefixes, but omits the remaining IPv6 transition forms that can embed a private IPv4 destination: 6to4 (`2002::/16`, RFC 3056), Teredo (`2001::/32`, RFC 4380), NAT64 (`64:ff9b::/96`, RFC 6052 and `64:ff9b:1::/48`, RFC 8215) and IPv4-compatible IPv6 (`::/96`, RFC 4291 §2.5.5.1). `IpUtils::checkIp6()` is a pure bitwise CIDR comparison against the constants list and never extracts the embedded IPv4, so an attacker who can supply a URL writes the loopback / RFC1918 IPv4 target as e.g. `http://[2002:7f00:1::]/` (6to4 → 127.0.0.1), `http://[64:ff9b::7f00:1]/` (NAT64 → 127.0.0.1), `http://[::7f00:1]/` (IPv4-compatible → 127.0.0.1) or `http://[2001::1]/` (Teredo). `IpUtils::isPrivateIp()` returns `false` and `NoPrivateNetworkHttpClient` dispatches the request. Real-world reachability of the embedded IPv4 depends on the deploy's IPv6 routing (6to4 tunnel interface, upstream NAT64 gateway, kernel handling of IPv4-compatible addresses), but the security boundary the decorator promises — the dispatch decision — is crossed regardless of whether the packet ultimately lands on the embedded IPv4. ### Resolution The private-subnet list now includes `::/96`, `2002::/16`, `2001::/32`, `64:ff9b::/96` and `64:ff9b:1::/48`. Blanket blocking of these prefixes matches the policy applied by Chromium and Mozilla's Private Network Access; server-side HTTPS APIs are not legitimately published on these prefixes. The patches for this issue are available [here](https://github.com/symfony/symfony/commit/82765368cf74177c36613575182f168a2eb765b2) for branch 5.4 and [here](https://github.com/symfony/symfony/commit/85b831555be8ea1f43bf01078afe87bc4c92f65e) for branch 6.4 (and forward-ported to 7.4, 8.0 and 8.1). ### Credits Symfony would like to thank tonghuaroot for reporting the issue and Nicolas Grekas for providing the fix.
Update symfony/http-client to 5.4.53; symfony/http-foundation to 6.4.41; symfony/http-foundation to 7.4.13; symfony/http-foundation to 8.0.13; symfony/symfony to 5.4.53; symfony/symfony to 6.4.41; symfony/symfony to 7.4.13; symfony/symfony to 8.0.13 if you use the affected versions. Test the change in a non-production environment first.
Local check
hol-guard supply-chain scanSymfony: IpUtils::PRIVATE_SUBNETS Omits IPv6 Transition Forms (6to4, NAT64, Teredo, IPv4-compatible): SSRF Bypass in NoPrivateNetworkHttpClient affects symfony/http-client (composer), symfony/http-foundation (composer), symfony/http-foundation (composer), symfony/http-foundation (composer), symfony/symfony (composer), symfony/symfony (composer), symfony/symfony (composer), symfony/symfony (composer). Severity is high. ### Description `Symfony\Component\HttpClient\NoPrivateNetworkHttpClient` is documented as a decorator that blocks requests to private networks by default. The list of blocked subnets (`Symfony\Component\HttpFoundation\IpUtils::PRIVATE_SUBNETS` on 6.4+, a private constant in `NoPrivateNetworkHttpClient` on 5.4) enumerates RFC1918, loopback, link-local and IPv4-mapped IPv6 (`::ffff:0:0/96`) prefixes, but omits the remaining IPv6 transition forms that can embed a private IPv4 destination: 6to4 (`2002::/16`, RFC 3056), Teredo (`2001::/32`, RFC 4380), NAT64 (`64:ff9b::/96`, RFC 6052 and `64:ff9b:1::/48`, RFC 8215) and IPv4-compatible IPv6 (`::/96`, RFC 4291 §2.5.5.1). `IpUtils::checkIp6()` is a pure bitwise CIDR comparison against the constants list and never extracts the embedded IPv4, so an attacker who can supply a URL writes the loopback / RFC1918 IPv4 target as e.g. `http://[2002:7f00:1::]/` (6to4 → 127.0.0.1), `http://[64:ff9b::7f00:1]/` (NAT64 → 127.0.0.1), `http://[::7f00:1]/` (IPv4-compatible → 127.0.0.1) or `http://[2001::1]/` (Teredo). `IpUtils::isPrivateIp()` returns `false` and `NoPrivateNetworkHttpClient` dispatches the request. Real-world reachability of the embedded IPv4 depends on the deploy's IPv6 routing (6to4 tunnel interface, upstream NAT64 gateway, kernel handling of IPv4-compatible addresses), but the security boundary the decorator promises — the dispatch decision — is crossed regardless of whether the packet ultimately lands on the embedded IPv4. ### Resolution The private-subnet list now includes `::/96`, `2002::/16`, `2001::/32`, `64:ff9b::/96` and `64:ff9b:1::/48`. Blanket blocking of these prefixes matches the policy applied by Chromium and Mozilla's Private Network Access; server-side HTTPS APIs are not legitimately published on these prefixes. The patches for this issue are available [here](https://github.com/symfony/symfony/commit/82765368cf74177c36613575182f168a2eb765b2) for branch 5.4 and [here](https://github.com/symfony/symfony/commit/85b831555be8ea1f43bf01078afe87bc4c92f65e) for branch 6.4 (and forward-ported to 7.4, 8.0 and 8.1). ### Credits Symfony would like to thank tonghuaroot for reporting the issue and Nicolas Grekas for providing the fix.
AI coding agents often install or upgrade packages automatically in composer. A high vulnerability in a dependency can be pulled into a project through a normal install or update without a human reviewing the change, expanding the blast radius from a single package to every agent workspace that depends on it.
| Package | Affected range | Fixed version |
|---|---|---|
| symfony/http-clientcomposer | >=5.4.0,<5.4.53 | 5.4.53 |
| symfony/http-foundationcomposer | >=6.4.0,<6.4.41 | 6.4.41 |
| symfony/http-foundationcomposer | >=7.0.0,<7.4.13 | 7.4.13 |
| symfony/http-foundationcomposer | >=8.0.0,<8.0.13 | 8.0.13 |
| symfony/symfonycomposer | >=5.4.0,<5.4.53 | 5.4.53 |
| symfony/symfonycomposer | >=6.4.0,<6.4.41 | 6.4.41 |
| symfony/symfonycomposer | >=7.0.0,<7.4.13 |
Reported by GitHub Security Advisories (ghsa).
HOL Guard can help your team review package activity against supported protection paths.
Explore HOL GuardUpdate symfony/http-client to 5.4.53; symfony/http-foundation to 6.4.41; symfony/http-foundation to 7.4.13; symfony/http-foundation to 8.0.13; symfony/symfony to 5.4.53; symfony/symfony to 6.4.41; symfony/symfony to 7.4.13; symfony/symfony to 8.0.13 if you use the affected versions. Test the change in a non-production environment first.
Local check
hol-guard supply-chain scanSymfony: IpUtils::PRIVATE_SUBNETS Omits IPv6 Transition Forms (6to4, NAT64, Teredo, IPv4-compatible): SSRF Bypass in NoPrivateNetworkHttpClient affects symfony/http-client (composer), symfony/http-foundation (composer), symfony/http-foundation (composer), symfony/http-foundation (composer), symfony/symfony (composer), symfony/symfony (composer), symfony/symfony (composer), symfony/symfony (composer). Severity is high. ### Description `Symfony\Component\HttpClient\NoPrivateNetworkHttpClient` is documented as a decorator that blocks requests to private networks by default. The list of blocked subnets (`Symfony\Component\HttpFoundation\IpUtils::PRIVATE_SUBNETS` on 6.4+, a private constant in `NoPrivateNetworkHttpClient` on 5.4) enumerates RFC1918, loopback, link-local and IPv4-mapped IPv6 (`::ffff:0:0/96`) prefixes, but omits the remaining IPv6 transition forms that can embed a private IPv4 destination: 6to4 (`2002::/16`, RFC 3056), Teredo (`2001::/32`, RFC 4380), NAT64 (`64:ff9b::/96`, RFC 6052 and `64:ff9b:1::/48`, RFC 8215) and IPv4-compatible IPv6 (`::/96`, RFC 4291 §2.5.5.1). `IpUtils::checkIp6()` is a pure bitwise CIDR comparison against the constants list and never extracts the embedded IPv4, so an attacker who can supply a URL writes the loopback / RFC1918 IPv4 target as e.g. `http://[2002:7f00:1::]/` (6to4 → 127.0.0.1), `http://[64:ff9b::7f00:1]/` (NAT64 → 127.0.0.1), `http://[::7f00:1]/` (IPv4-compatible → 127.0.0.1) or `http://[2001::1]/` (Teredo). `IpUtils::isPrivateIp()` returns `false` and `NoPrivateNetworkHttpClient` dispatches the request. Real-world reachability of the embedded IPv4 depends on the deploy's IPv6 routing (6to4 tunnel interface, upstream NAT64 gateway, kernel handling of IPv4-compatible addresses), but the security boundary the decorator promises — the dispatch decision — is crossed regardless of whether the packet ultimately lands on the embedded IPv4. ### Resolution The private-subnet list now includes `::/96`, `2002::/16`, `2001::/32`, `64:ff9b::/96` and `64:ff9b:1::/48`. Blanket blocking of these prefixes matches the policy applied by Chromium and Mozilla's Private Network Access; server-side HTTPS APIs are not legitimately published on these prefixes. The patches for this issue are available [here](https://github.com/symfony/symfony/commit/82765368cf74177c36613575182f168a2eb765b2) for branch 5.4 and [here](https://github.com/symfony/symfony/commit/85b831555be8ea1f43bf01078afe87bc4c92f65e) for branch 6.4 (and forward-ported to 7.4, 8.0 and 8.1). ### Credits Symfony would like to thank tonghuaroot for reporting the issue and Nicolas Grekas for providing the fix.
AI coding agents often install or upgrade packages automatically in composer. A high vulnerability in a dependency can be pulled into a project through a normal install or update without a human reviewing the change, expanding the blast radius from a single package to every agent workspace that depends on it.
| Package | Affected range | Fixed version |
|---|---|---|
| symfony/http-clientcomposer | >=5.4.0,<5.4.53 | 5.4.53 |
| symfony/http-foundationcomposer | >=6.4.0,<6.4.41 | 6.4.41 |
| symfony/http-foundationcomposer | >=7.0.0,<7.4.13 | 7.4.13 |
| symfony/http-foundationcomposer | >=8.0.0,<8.0.13 | 8.0.13 |
| symfony/symfonycomposer | >=5.4.0,<5.4.53 | 5.4.53 |
| symfony/symfonycomposer | >=6.4.0,<6.4.41 | 6.4.41 |
| symfony/symfonycomposer | >=7.0.0,<7.4.13 |
Reported by GitHub Security Advisories (ghsa).
HOL Guard can help your team review package activity against supported protection paths.
Explore HOL Guard| 7.4.13 |
| symfony/symfonycomposer | >=8.0.0,<8.0.13 | 8.0.13 |
|---|
Fixed versions are reported by the source feed; confirm compatibility before updating.
| 7.4.13 |
| symfony/symfonycomposer | >=8.0.0,<8.0.13 | 8.0.13 |
|---|
Fixed versions are reported by the source feed; confirm compatibility before updating.