Symfony is a PHP framework for web and console applications and a set of reusable PHP components. Prior to 7.4.13 and 8.0.13, MailomatRequestParser::validateSignature() parsed X-MOM-Webhook-Signature as algo=signature and passed the request-selected algorithm to hash_hmac(), allowing a signature algorithm downgrade instead of enforcing Mailomat's documented SHA-256 webhook signature. This issue is fixed in versions 7.4.13 and 8.0.13.
CVE-2026-48747
This medium-severity CVE scores 5.3 under NVD CVSS v3. EPSS exploit probability: 0.2%, top 84% 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).
- Lower severity and no public exploit yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 5.3
- EG Score
- 5.3(medium)
- EG Risk
- 24(Track)EG Risk 24/100SSVC: 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 computedSeverity53% × 45%Exploitation0% × 40%Automatability0% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 16%
- KEV
- Not listed
Published
June 15, 2026
Last Modified
July 15, 2026
Advisory Details (4)
Auto-updated Jul 19, 2026Mailomat Mailer Webhook Parser Reads the HMAC Algorithm from the Request: Signature Algorithm Downgrade · Advisory · symfony/symfony · GitHub
https://github.com/symfony/symfony/security/advisories/GHSA-rrj9-5q2j-4gvrv8.0.13
Patch available: symfony/symfony v8.0.13
https://github.com/symfony/symfony/releases/tag/v8.0.13v7.4.13
Patch available: symfony/symfony v7.4.13
https://github.com/symfony/symfony/releases/tag/v7.4.13commit bdfe9fe0d94d (symfony/symfony)
Patch available: symfony/symfony v7.4.13 (contains commit bdfe9fe0d94d)
https://github.com/symfony/symfony/commit/bdfe9fe0d94d33dfaca0bc2fe0b00b54767b0c88Vendor Advisories for CVE-2026-48747(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)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| symfony/mailomat-mailer | v8.0.0 | 8.0.13 | — |
| symfony/symfony | v8.0.0 ... v8.0.9 (13 versions) | 8.0.13 | — |
Debian:14(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| symfony | 6.4.21+dfsg-2 ... 7.4.9+dfsg-1 (53 versions) | 7.4.13+dfsg-1 | — |
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 10× in last 7d / 47× 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.
- 2026-08-25 13:49 UTCEPSS rescore
- 2026-08-24 23:34 UTCEG score recompute
- 2026-08-23 09:48 UTCEG score recompute
- 2026-08-23 00:19 UTCEPSS rescore
- 2026-08-21 23:49 UTCEPSS rescore
- 2026-08-21 17:44 UTCEG score recompute
- 2026-08-20 22:55 UTCEPSS rescore
- 2026-08-20 16:21 UTCEG score recompute
- 2026-08-19 17:04 UTCEPSS rescore
- 2026-08-19 13:14 UTCEG score recompute
- 2026-08-18 13:48 UTCEPSS rescore
- 2026-08-17 13:47 UTCEPSS rescore
- 2026-08-16 22:51 UTCEG score recompute
- 2026-08-16 14:56 UTCEPSS rescore
- 2026-08-16 02:14 UTCEPSS rescore
- 2026-08-15 23:14 UTCEG score recompute
- 2026-08-15 01:30 UTCEPSS rescore
- 2026-08-13 22:04 UTCEG score recompute
- 2026-08-13 22:00 UTCEPSS rescore
- 2026-08-12 18:51 UTCEG score recompute
- 2026-08-12 13:51 UTCEPSS rescore
- 2026-08-11 19:14 UTCEG score recompute
- 2026-08-11 00:00 UTCEPSS rescore
- 2026-08-09 18:10 UTCEG score recompute
- 2026-08-09 13:46 UTCEPSS rescore
Show 42 moreShow fewer
- 2026-08-08 18:33 UTCEG score recompute
- 2026-08-08 16:37 UTCEPSS rescore
- 2026-08-07 18:56 UTCEG score recompute
- 2026-08-06 19:19 UTCEG score recompute
- 2026-08-06 13:47 UTCEPSS rescore
- 2026-08-05 19:42 UTCEG score recompute
- 2026-08-05 19:17 UTCEPSS rescore
- 2026-08-04 15:42 UTCEG score recompute
- 2026-08-04 15:10 UTCEPSS rescore
- 2026-08-04 10:39 UTCEPSS rescore
- 2026-08-03 10:36 UTCEPSS rescore
- 2026-08-02 08:28 UTCEG score recompute
- 2026-08-02 02:27 UTCEPSS rescore
- 2026-08-01 08:51 UTCEG score recompute
- 2026-08-01 04:16 UTCEPSS rescore
- 2026-07-31 04:49 UTCEG score recompute
- 2026-07-30 16:28 UTCEPSS rescore
- 2026-07-30 05:12 UTCEG score recompute
- 2026-07-30 01:30 UTCEPSS rescore
- 2026-07-29 03:26 UTCEG score recompute
- 2026-07-28 15:37 UTCEPSS rescore
- 2026-07-28 01:54 UTCEG score recompute
- 2026-07-26 20:13 UTCEG score recompute
- 2026-07-26 14:54 UTCEPSS rescore
- 2026-07-25 14:18 UTCEPSS rescore
- 2026-07-24 14:18 UTCEPSS rescore
- 2026-07-23 14:18 UTCEPSS rescore
- 2026-07-23 03:18 UTCEG score recompute
- 2026-07-22 14:08 UTCEPSS rescore
- 2026-07-21 15:25 UTCEPSS rescore
- 2026-07-20 17:08 UTCEPSS rescore
- 2026-07-19 14:31 UTCEPSS rescore
- 2026-07-19 14:31 UTCEPSS rescore
- 2026-07-19 02:29 UTCEPSS rescore
- 2026-07-18 10:04 UTCEPSS rescore
- 2026-07-16 17:03 UTCEPSS rescore
- 2026-07-15 19:48 UTCEG score recompute▼ 1.00
- 2026-07-15 16:57 UTCEPSS rescore
- 2026-07-15 16:23 UTCNVD updateCVSS v3 → 5.3
- 2026-07-14 19:34 UTCEG score recompute▲ 6.30
- 2026-07-14 19:31 UTCMITRE cvelistV5CVSS v3 → 6.3 · CVSS v4 → 6.3
- 2026-06-15 17:45 UTCEG score recompute
Frequently asked(5)
What is CVE-2026-48747?
When was CVE-2026-48747 disclosed?
Is CVE-2026-48747 actively exploited?
What is the CVSS score of CVE-2026-48747?
How do I remediate CVE-2026-48747?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-48747
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