CVE-2026-45755

MEDIUMNVD 5.35.3—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.3 under NVD CVSS v3. EPSS exploit probability: 0.3%, top 82% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
5.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.3Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Symfony is a PHP framework for web and console applications and a set of reusable PHP components. Prior to 7.4.12 and 8.0.12, MailtrapRequestParser::doParse() received the configured webhook secret but ignored the X-Mt-Signature HMAC header, allowing unauthenticated POST requests to inject forged Mailtrap delivery, bounce, open, click, or spam events. This issue is fixed in versions 7.4.12 and 8.0.12.

CVSS v3
5.3
EG Score
5.3(medium)
EG Risk
39(Track)
EG Risk 39/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity53% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
19%
KEV
Not listed

Published

May 28, 2026

Last Modified

July 15, 2026

Advisory Details (4)

Auto-updated Jul 15, 2026
Patch available. Sources: github_commit, github_release, github.
github Patch Available

Mailtrap Mailer Webhook Parser Never Verifies the X-Mt-Signature HMAC: Unauthenticated Webhook Event Injection · Advisory · symfony/symfony · GitHub

https://github.com/symfony/symfony/security/advisories/GHSA-59f3-vp2f-mp9w
github_release Patch Available

v8.0.12

Patch available: symfony/symfony v8.0.12

https://github.com/symfony/symfony/releases/tag/v8.0.12
github_release Patch Available

v7.4.12

Patch available: symfony/symfony v7.4.12

https://github.com/symfony/symfony/releases/tag/v7.4.12
github_commit Patch Available

commit 4e0467e4e182 (symfony/symfony)

Patch available: symfony/symfony v7.4.12 (contains commit 4e0467e4e182)

https://github.com/symfony/symfony/commit/4e0467e4e182cf2e704a3d9e1bc1a6be65d52ab8

Vendor Advisories for CVE-2026-45755(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(3 across 2 ecosystems)
Packagist(2)
PackageVulnerable rangeFixed inDependents
symfony/mailtrap-mailerv8.0.08.0.12—
symfony/symfonyv8.0.0 ... v8.0.9 (12 versions)8.0.12—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
symfony6.4.21+dfsg-2 ... 7.4.9+dfsg-1 (52 versions)7.4.12+dfsg-1—

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 5× in last 7d / 38× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-09-04 05:06 UTCEPSS rescore
  2. 2026-09-02 14:12 UTCEPSS rescore
  3. 2026-09-01 13:54 UTCEPSS rescore
  4. 2026-08-30 19:17 UTCEPSS rescore
  5. 2026-08-30 01:22 UTCEPSS rescore
  6. 2026-08-28 21:41 UTCEPSS rescore
  7. 2026-08-27 14:25 UTCEPSS rescore
  8. 2026-08-26 14:46 UTCEPSS rescore
  9. 2026-08-25 13:49 UTCEPSS rescore
  10. 2026-08-25 04:40 UTCEG score recompute
  11. 2026-08-23 14:28 UTCEG score recompute
  12. 2026-08-23 00:19 UTCEPSS rescore
  13. 2026-08-21 23:49 UTCEPSS rescore
  14. 2026-08-21 15:25 UTCEG score recompute
  15. 2026-08-20 22:55 UTCEPSS rescore
  16. 2026-08-20 10:45 UTCEG score recompute
  17. 2026-08-19 17:04 UTCEPSS rescore
  18. 2026-08-18 13:48 UTCEPSS rescore
  19. 2026-08-17 13:47 UTCEPSS rescore
  20. 2026-08-17 07:59 UTCEG score recompute
  21. 2026-08-16 14:56 UTCEPSS rescore
  22. 2026-08-16 02:33 UTCEG score recompute
  23. 2026-08-16 02:14 UTCEPSS rescore
  24. 2026-08-15 01:30 UTCEPSS rescore
  25. 2026-08-14 00:57 UTCEG score recompute
Show 51 more
  1. 2026-08-13 22:00 UTCEPSS rescore
  2. 2026-08-13 00:00 UTCEG score recompute
  3. 2026-08-12 13:51 UTCEPSS rescore
  4. 2026-08-12 00:03 UTCEG score recompute
  5. 2026-08-11 00:05 UTCEG score recompute
  6. 2026-08-11 00:00 UTCEPSS rescore
  7. 2026-08-09 23:55 UTCEG score recompute
  8. 2026-08-09 13:46 UTCEPSS rescore
  9. 2026-08-08 23:58 UTCEG score recompute
  10. 2026-08-08 16:37 UTCEPSS rescore
  11. 2026-08-08 00:01 UTCEG score recompute
  12. 2026-08-07 00:04 UTCEG score recompute
  13. 2026-08-06 13:47 UTCEPSS rescore
  14. 2026-08-05 23:37 UTCEG score recompute
  15. 2026-08-05 19:17 UTCEPSS rescore
  16. 2026-08-04 23:40 UTCEG score recompute
  17. 2026-08-04 15:10 UTCEPSS rescore
  18. 2026-08-04 10:39 UTCEPSS rescore
  19. 2026-08-02 14:24 UTCEG score recompute
  20. 2026-08-02 02:27 UTCEPSS rescore
  21. 2026-08-01 14:27 UTCEG score recompute
  22. 2026-08-01 04:16 UTCEPSS rescore
  23. 2026-07-31 06:19 UTCEG score recompute
  24. 2026-07-30 16:28 UTCEPSS rescore
  25. 2026-07-30 01:30 UTCEPSS rescore
  26. 2026-07-29 12:31 UTCEG score recompute
  27. 2026-07-28 15:36 UTCEPSS rescore
  28. 2026-07-27 14:13 UTCEPSS rescore
  29. 2026-07-27 09:37 UTCEG score recompute
  30. 2026-07-26 14:54 UTCEPSS rescore
  31. 2026-07-26 14:54 UTCEPSS rescore
  32. 2026-07-25 14:18 UTCEPSS rescore
  33. 2026-07-24 14:17 UTCEPSS rescore
  34. 2026-07-23 14:18 UTCEPSS rescore
  35. 2026-07-23 03:16 UTCEG score recompute
  36. 2026-07-22 14:08 UTCEPSS rescore
  37. 2026-07-21 15:24 UTCEPSS rescore
  38. 2026-07-20 17:08 UTCEPSS rescore
  39. 2026-07-19 14:31 UTCEPSS rescore
  40. 2026-07-19 02:29 UTCEPSS rescore
  41. 2026-07-18 10:04 UTCEPSS rescore
  42. 2026-07-16 17:03 UTCEPSS rescore
  43. 2026-07-16 02:52 UTCEG score recompute▼ 1.60
  44. 2026-07-15 16:57 UTCEPSS rescore
  45. 2026-07-15 14:22 UTCNVD updateCVSS v3 → 5.3
  46. 2026-07-14 19:03 UTCEG score recompute▲ 6.90
  47. 2026-07-14 19:00 UTCMITRE cvelistV5CVSS v3 → 6.9 · CVSS v4 → 6.9
  48. 2026-06-14 23:18 UTCEPSS rescore
  49. 2026-06-13 23:00 UTCEPSS rescore
  50. 2026-06-12 23:12 UTCEPSS rescore
  51. 2026-05-28 18:06 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-45755?
CVE-2026-45755 is a medium vulnerability published on May 28, 2026. Symfony is a PHP framework for web and console applications and a set of reusable PHP components. Prior to 7.4.12 and 8.0.12, MailtrapRequestParser::doParse() received the configured webhook secret but ignored the X-Mt-Signature HMAC header, allowing unauthenticated POST requests to inject forged…
When was CVE-2026-45755 disclosed?
CVE-2026-45755 was first published in the National Vulnerability Database on May 28, 2026, with the most recent update on July 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-45755 actively exploited?
CVE-2026-45755 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 81.4% of all scored CVEs.
What is the CVSS score of CVE-2026-45755?
CVE-2026-45755 has a CVSS v3 base score of 5.3 (NVD).
How do I remediate CVE-2026-45755?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-45755, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-45755

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