The SimpleSAMLphp SAML2 library is a PHP library for SAML2 related functionality. Prior to versions 4.19.3, 4.20.2, 5.0.6, and 6.2.1, the HTTPArtifact::receive() flow can treat an unsigned embedded SAML Response as cryptographically valid for the wrong identity provider. SOAPClient::addSSLValidator() attaches a TLS-based validator to the outer SOAP ArtifactResponse, while the embedded Response receives a validator that delegates to the outer message and is later checked against metadata selected from the embedded response issuer rather than necessarily the artifact issuer. SOAPClient::validateSSL() returns normally when the TLS public key does not match the key being validated, and SAML2\Message::validate() treats a validator call that does not throw as successful. In a multi-IdP federation, a malicious or lower-trust IdP can therefore provide an ArtifactResponse containing an unsigned Response that claims a higher-trust victim IdP as issuer and authenticate as arbitrary users with attacker-chosen assertion attributes, NameID, and session data. This issue is fixed in versions 4.19.3, 4.20.2, 5.0.6, and 6.2.1.
CVE-2026-49283
“—” beside the score: it is equal to the CVSS score beside it.
Score 8.7 from GitHub Security Advisory (severity: HIGH) published 2026-07-02. A secondary CVSS source baseline 8.7; sources differ by 0.0.
Also known asEUVD-2026-62502 (ENISA EUVD) · GHSA-6929-8p9f-26jx (GitHub Security Advisories)Source: ENISA EUVD
- High severity, but no confirmed exploitation yet
A fix is available — apply it.
- CVSS v3
- 8.7
- EG Score
- 8.7HIGHmedium confidence
- EG Risk
- 39EG Risk 39/100
EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.
How it’s computed (value × EchelonGraph’s weight)Severity87% × 45%Impact severity (EG Severity): CVSS 8.7 of 10. Never the KEV-floored or EPSS-lifted EG Score.Exploitation0.5% × 40%FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.Automatability0% × 15%CISA's SSVC Automatable value: no (Vulnrichment).SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.Action: A fix is available. Apply it within your standard update timelines. - EPSS PROB
- 0.5%
- EPSS %ILE
- 40th
- KEV
- Not listed
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (8.7): severity, escalated by confirmed exploitation. This CVE's 8.7 is its impact severity (EG Severity), not escalated.
- EG Severity
- 8.7 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- 0.5% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-31). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).
A fix is available. Apply it within your standard update timelines.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it
Published
July 2, 2026
Last Modified
September 18, 2026
Advisory Details (5)
Auto-updated Aug 19, 2026commit e2df79926099 (simplesamlphp/saml2)
Fix landed in simplesamlphp/saml2 commit e2df79926099 — awaiting tagged release
https://github.com/simplesamlphp/saml2/commit/e2df7992609964951b2a3e7d6566b7427b2a968fcommit d5c213132ef6 (simplesamlphp/saml2)
Fix landed in simplesamlphp/saml2 commit d5c213132ef6 — awaiting tagged release
https://github.com/simplesamlphp/saml2/commit/d5c213132ef671c0018a11252322034dbddd735acommit a2c1ac588c70 (simplesamlphp/saml2)
Fix landed in simplesamlphp/saml2 commit a2c1ac588c70 — awaiting tagged release
https://github.com/simplesamlphp/saml2/commit/a2c1ac588c70d7b7998546cf32675fb113f22a5fcommit 4a71b20d8d84 (simplesamlphp/saml2)
Patch available: simplesamlphp/saml2 v7.0.0-rc1 (contains commit 4a71b20d8d84)
https://github.com/simplesamlphp/saml2/commit/4a71b20d8d845579fd0a54d6449c265b40db459dSimpleSAMLphp HTTP-Artifact TLS validator confusion allows cross-IdP authentication bypass · Advisory · simplesamlphp/saml2 · GitHub
https://github.com/simplesamlphp/saml2/security/advisories/GHSA-6929-8p9f-26jxVendor Advisories for CVE-2026-49283(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Patch Availability(4)
| Vendor / Ecosystem | Fix (by version range) / Patch | Released | Source |
|---|---|---|---|
| composer | simplesamlphp/saml2 @ 6.2.1 (fixes >= 6.0.0, < 6.2.1) | — | ghsa |
| composer | simplesamlphp/saml2 @ 5.0.6 (fixes >= 5.0.0, < 5.0.6) | — | ghsa |
| composer | simplesamlphp/saml2 @ 4.20.2 (fixes >= 4.20.0, < 4.20.2) | — | ghsa |
| composer | simplesamlphp/saml2 @ 4.19.3 (fixes < 4.19.3) | — | ghsa |
Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.
Affected Packages
(4 across 3 ecosystems)
Packagist(2)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| simplesamlphp/saml2 | 4.6.9 ... v4.6.8 (152 versions) |
| — |
| simplesamlphp/saml2-legacy | 4.6.9 ... v4.6.8 (150 versions) |
| — |
Debian:12(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| simplesamlphp | 1.19.7-1 ... 2.5.3.1-1 (10 versions) |
| — |
Debian:14(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| simplesamlphp | 1.10.0-1 ... 2.5.3.1-1 (75 versions) |
| — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 10× in last 7d / 42× in last 30d)
Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.
- 2026-11-02 16:45 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-11-01 16:34 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-11-01 07:46 UTCGHSA enrichmentGHSA-6929-8p9f-26jx · GitHub severity HIGH · GitHub CVSS 8.7
- 2026-11-01 07:46 UTCEG score recompute
- 2026-10-31 16:32 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-10-30 10:40 UTCEG score recompute
- 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-10-25 14:22 UTCEG score recompute
- 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-10-23 23:55 UTCEG score recompute
- 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-10-18 03:34 UTCEG score recompute
- 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-10-17 12:00 UTCEG score recompute
- 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.5% · 39th percentile
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- 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-10-13 14:54 UTCOSV refresh
- 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.5% · 38th percentile
- 2026-10-12 16:00 UTCEG score recompute
- 2026-10-11 19:43 UTCEG score recompute
- 2026-10-11 16:57 UTCEG score recompute
- 2026-10-11 14:21 UTCEG score recompute
- 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.5% · 38th percentile
- 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.5% · 38th percentile
- 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.5% · 38th percentile
- 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.5% · 38th percentile
- 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.5% · 38th percentile
- 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.5% · 38th percentile
- 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.5% · 38th percentile
- 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.5% · 38th percentile
- 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.5% · 38th percentile
- 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.5% · 38th percentile
- 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.5% · 38th percentile
- 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.5% · 38th percentile
- 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.5% · 38th percentile
- 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.5% · 38th percentile
- 2026-09-26 00:27 UTCEPSS rescoreEPSS 0.5% · 38th percentile
- 2026-09-23 17:53 UTCEPSS rescoreEPSS 0.3% · 28th percentile
- 2026-09-23 06:38 UTCEG score recompute
- 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.3% · 28th percentile
- 2026-09-18 20:35 UTCEG score recompute
- 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.3% · 27th percentile
- 2026-09-18 06:14 UTCEG score recompute
- 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.3% · 27th percentile
- 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.3% · 27th percentile
- 2026-09-14 00:15 UTCEG score recompute
- 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.3% · 27th percentile
- 2026-09-13 08:59 UTCEG score recompute
- 2026-09-12 14:15 UTCEG score recompute
- 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.3% · 27th percentile
- 2026-09-10 09:35 UTCEPSS rescoreEPSS 0.3% · 27th percentile
- 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.3% · 27th percentile
- 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.3% · 27th percentile
- 2026-09-06 14:19 UTCEG score recompute
- 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.3% · 27th percentile
- 2026-09-05 23:52 UTCEG score recompute
- 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.3% · 27th percentile
- 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.3% · 27th percentile
- 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.3% · 27th percentile
- 2026-09-01 04:40 UTCEPSS rescoreEPSS 0.3% · 27th percentile
- 2026-08-30 22:20 UTCEG score recompute
- 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.3% · 27th percentile
- 2026-08-30 11:22 UTCEG score recompute
- 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.3% · 27th percentile
- 2026-08-28 21:41 UTCEPSS rescoreEPSS 0.3% · 27th percentile
- 2026-08-27 22:14 UTCEG score recompute
- 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.3% · 27th percentile
- 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.3% · 27th percentile
- 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.3% · 26th percentile
- 2026-08-24 15:05 UTCEG score recompute
- 2026-08-23 06:20 UTCEG score recompute
- 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.3% · 27th percentile
- 2026-08-22 06:26 UTCEG score recompute
- 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.3% · 27th percentile
- 2026-08-21 04:27 UTCEG score recompute
- 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.3% · 27th percentile
- 2026-08-19 19:21 UTCEG score recompute
- 2026-08-19 18:23 UTCEG score recompute
- 2026-08-19 15:31 UTCEG score recompute
- 2026-07-30 17:18 UTCEG score recompute
- 2026-07-26 13:02 UTCEG score recompute
- 2026-07-23 03:18 UTCEG score recompute
- 2026-07-02 21:07 UTCEG score recompute
Related CVEs(same product + same CWE)
Same product
10 shownPackagist:simplesamlphp/saml2-legacy · Packagist:simplesamlphp/saml2 · Debian:12:simplesamlphp
Frequently asked(5)
What is CVE-2026-49283?
When was the CVE record for CVE-2026-49283 published?
Is CVE-2026-49283 actively exploited?
What is the CVSS score of CVE-2026-49283?
How do I remediate CVE-2026-49283?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-49283
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