dbcve.org
SymfonyFramework / library · Sensiolabs

CVE-2026-45068

HIGH · 7.5 CVSS v3.1 Published 2026-07-14
Fix available
A fix is available. Upgrade to 5.4.52 / 6.4.40 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click 5 weeks old

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Symfony is a PHP framework for web and console applications and a set of reusable PHP components. Prior to 5.4.52, 6.4.40, 7.4.12, and 8.0.12, SendmailTransport in -t mode appended recipient addresses to the sendmail command line without a -- end-of-options separator, allowing an address beginning with - to be interpreted as a sendmail command-line option instead of an address. This issue is fixed in versions 5.4.52, 6.4.40, 7.4.12, and 8.0.12.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

SendmailTransport in Symfony's Mailer component appends recipient addresses to the sendmail command line in -t mode without a '--' end-of-options separator. This allows an attacker-controlled recipient address starting with '-' to be interpreted as a sendmail command-line option rather than a mail recipient, potentially enabling option injection.

MitigationUpgrade Symfony to version 5.4.52, 6.4.40, 7.4.12, or 8.0.12 which adds the proper '--' separator to prevent option injection.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
SymfonyFramework / library
Affected:< 5.4.52>= 6.0.0, < 6.4.40>= 7.0.0, < 7.4.12>= 8.0.0, < 8.0.12

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check Symfony version
    Run 'composer show symfony/symfony' or inspect the version in your composer.lock file to determine the installed Symfony version.
    Affected if The installed version is < 5.4.52, OR >= 6.0.0 and < 6.4.40, OR >= 7.0.0 and < 7.4.12, OR >= 8.0.0 and < 8.0.12.
  2. Verify SendmailTransport is in use
    Check your mailer configuration file (typically config/packages/mailer.yaml or config/services.yaml) for a DSN using 'sendmail://default' or a custom sendmail transport configuration.
    Affected if The mailer DSN begins with 'sendmail://' indicating SendmailTransport is being used.
  3. Confirm sendmail -t mode is configured
    Examine the mailer configuration for any 'header_charset', 'command', or 'arguments' settings that enable -t mode for the sendmail binary, or inspect the actual command passed to the sendmail binary at runtime.
    Affected if The sendmail transport is configured to use the -t option (look for -t in the command arguments or default -t behavior is active).
  4. Check for user-controlled recipient injection
    Audit your application code that handles email recipients, particularly any paths where user input flows into the 'to', 'cc', 'bcc', or 'headers' of emails sent via the SendmailTransport.
    Affected if User-supplied data can reach email recipient addresses without sanitization, allowing addresses to start with a dash character.

You are affected if you are running a vulnerable Symfony version AND using SendmailTransport with sendmail -t mode, and your application allows attacker-controlled input to become email recipients.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 5.4.52 / 6.4.40 / 7.4.12 or later
Fixed in 5.4.526.4.407.4.12
Interim mitigation

Upgrade Symfony to version 5.4.52, 6.4.40, 7.4.12, or 8.0.12 which adds the proper '--' separator to prevent option injection.

Recommended fix High confidence

Upgrade to 5.4.52 (5.x), 6.4.40 (6.x), 7.4.12 (7.x), or 8.0.12 (8.x) depending on your current branch

  1. Identify the current Symfony version in use by checking your composer.json or installed version
  2. Determine which version branch you're currently on (5.x, 6.x, 7.x, or 8.x)
  3. Run composer require symfony/symfony:"<target_version>" --update-with-all-dependencies, replacing <target_version> with: 5.4.52 if on 5.x, 6.4.40 if on 6.x, 7.4.12 if on 7.x, or 8.0.12 if on 8.x
  4. Alternatively, run composer update symfony/symfony to get the latest compatible version in your branch
  5. After upgrading, test email functionality to ensure SendmailTransport works correctly
  6. Verify the fix by confirming that email addresses beginning with - are now properly treated as addresses and not as command-line options
Caveat Minor patch release unlikely to introduce breaking changes; standard Symfony upgrade precautions apply

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Symfony Scoped from the published advisory
  • Consultation3.0 h
  • Implementation2.0 h
  • Testing6.0 h
  • Review / QA2.0 h
13.0 hours of engineering $2,220
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,552.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-45068 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data