Advisory details:
github_osv / GHSA-m7v2-7gxm-vc2v
| Advisory ID | github_osv/GHSA-m7v2-7gxm-vc2v |
| Aliases |
CVE-2026-45077
|
| Summary | Symfony has Unauthenticated PHP Object Deserialization in MonologBridge server:log Listener ### Description `Symfony\Bridge\Monolog\Command\ServerLogCommand` (the `server:log` console command) is a development-time helper that opens a TCP listener and displays log records pushed to it by the application's logging pipeline. Two unsafe defaults combine into a remotely reachable PHP object-deserialization sink: 1. The listener binds to `0.0.0.0:9911` by default; it accepts connections on every interface, not only loopback. 2. Each received frame is processed as `unserialize(base64_decode($message))` without an `allowed_classes` allowlist, without authentication, and without any integrity check. The decoded value is then passed to `displayLog(..., array $record)` which assumes (without validating) that the result is an array. Any host that can reach TCP port 9911 on a machine running `server:log` can therefore submit attacker-chosen serialized PHP payloads. The minimum impact is an unauthenticated denial of service (sending a non-array, e.g. `serialize(new stdClass())`, crashes the listener with a type error). Object injection with magic-method side effects (`__wakeup()` / `__destruct()` / etc.) is reachable before the array type-check fires; full remote code execution is environment-dependent and contingent on usable gadget chains in the autoload set of the target process. ### Resolution The `server:log` command no longer binds to all interfaces by default: the default `--host` is now `127.0.0.1:9911`, requiring explicit opt-in to accept off-host traffic. Message decoding is gated by an `unserialize()` allowlist restricted to the `Symfony\Component\VarDumper\Caster\*` and `Symfony\Component\VarDumper\Cloner\*` classes that legitimately appear inside dumped log records; any other class is rejected and the record discarded. The patch for this issue is available [here](https://github.com/symfony/symfony/commit/0891b2f293896c488e26943dc034334364b77fc4) for branch 5.4. ### Credits Symfony would like to thank Toàn Thắng and Sam Sanoop for reporting the issue and Nicolas Grekas for fixing it. |
| Status | Published |
| Exploitability | 0.5 |
| Weighted Severity | 7.3 |
| Risk | 3.6 |
| Affected and Fixed Packages | Package Details |
| Introduced and Fixed Package Commit Patches | Package Commit Patches Details |
| System | Score | Found at |
|---|---|---|
| cvssv4 | 8.1 | https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-m7v2-7gxm-vc2v/GHSA-m7v2-7gxm-vc2v.json |
| generic_textual | HIGH |
No EPSS data available for this advisory.
| Patch URL | |
|---|---|
| There are no known patches. | |
| Attack Vector (AV) | Attack Complexity (AC) | Attack Requirements (AT) | Privileges Required (PR) | User Interaction (UI) | Vulnerable System Impact Confidentiality (VC) | Vulnerable System Impact Integrity (VI) | Vulnerable System Impact Availability (VA) | Subsequent System Impact Confidentiality (SC) | Subsequent System Impact Integrity (SI) | Subsequent System Impact Availability (SA) |
|---|---|---|---|---|---|---|---|---|---|---|
network adjacent local physical |
low high |
none present |
none low high |
none passive active |
high low none |
high low none |
high low none |
high low none |
high low none |
high low none |
Vector: SSVCv2/E:N/A:N/T:P/P:M/B:A/M:M/D:T/2026-07-14T18:24:06Z/
Decision: Track
Source URL: https://github.com/cisagov/vulnrichment/blob/develop/2026/45xxx/CVE-2026-45077.json
Source Advisory: vulnrichment/CVE-2026-45077
[{'Exploitation': 'none'},
{'Automatable': 'no'},
{'Technical Impact': 'partial'},
{'Mission Prevalence': 'minimal'},
{'Public Well-being Impact': 'material'},
{'Mission & Well-being': 'medium'}]