joserfc is a Python library that provides an implementation of several JSON Object Signing and Encryption (JOSE) standards. In versions 1.3.4 through 1.6.5, joserfc accepts oversized RFC7797 b64=false JWS payloads without applying JWSRegistry.max_payload_length, which can lead to resource exhaustion. The normal JWS compact and flattened JSON paths reject payloads above the configured payload-size limit with ExceededSizeError. The RFC7797 unencoded payload paths do not make the same check. A valid b64=false compact or flattened JSON JWS can therefore deserialize successfully with a payload larger than JWSRegistry.max_payload_length. Applications that accept lower-trust JWS values and rely on joserfc to reject oversized token content during verification have a moderate availability risk. This issue has been fixed in version 1.6.7.
CVE-2026-48990
“—” beside the score: it is equal to the CVSS score beside it.
This medium-severity CVE scores 5.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3% (17th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.
- CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
A fix is available — apply it.
- CVSS v3
- 5.3
- EG Score
- 5.3MEDIUMmedium confidence
- EG Risk
- 55EG Risk 55/100
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)Severity53% × 45%Impact severity (EG Severity): CVSS 5.3 of 10. Never the KEV-floored or EPSS-lifted EG Score.Exploitation40% × 40%EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.Automatability100% × 15%CISA's SSVC Automatable value: yes (Vulnrichment).SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).Exploitation public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (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 at low or medium mission impact and sooner than that at high. - EPSS PROB
- 0.3%
- EPSS %ILE
- 17th
- 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 (5.3): severity, escalated by confirmed exploitation. This CVE's 5.3 is its impact severity (EG Severity), not escalated.
- EG Severity
- 5.3 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.a secondary CVSS source · CVSS v3.0 or v3.1
- EG Likelihood
- 0.3% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-17). 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; Attend at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; 60 days if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Attend at high (mission-essential systems).
A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
Exploitation public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (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; 60 days if it is not.
In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact partial (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
June 17, 2026
Last Modified
June 23, 2026
Advisory Details (2)
Auto-updated Jun 17, 2026RFC7797 b64=false JWS payloads bypass JWSRegistry payload-size limits during deserialization · Advisory · authlib/joserfc · GitHub
https://github.com/authlib/joserfc/security/advisories/GHSA-wphv-vfrh-23q51.6.7
Patch available: authlib/joserfc 1.6.7
https://github.com/authlib/joserfc/releases/tag/1.6.7Vendor Advisories for CVE-2026-48990(5)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
- RHSA-2026:50479Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat Ansible Automation Platform 2.6 Container Release Update
- RHSA-2026:50340Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat Ansible Automation Platform 2.7 Container Release Update
- RHSA-2026:43038Red Hat Product SecurityCritical
Red Hat Security Advisory: Migration Toolkit for Applications
- GHSA-wphv-vfrh-23q5GitHub Security AdvisoriesMedium
joserfc: b64=false RFC7797 JWS payloads bypass JWSRegistry payload-size limits during deserialization
- RHSA-2026:25039Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update
Patch Availability(4)
| Vendor / Ecosystem | Fix (by version range) / Patch | Released | Source |
|---|---|---|---|
| redhat | ansible-automation-platform-26/lightspeed-chatbot-rhel9:1785646188 | 2026-08-04 | redhat |
| redhat | ansible-automation-platform-27/lightspeed-chatbot-rhel9:1785426734 | 2026-08-04 | redhat |
| redhat | mta/mta-solution-server-rhel9:1784109883 | 2026-07-21 | redhat |
| redhat | jaeger-main-2.19.0-1.hum1 | 2026-06-10 | redhat |
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
(3 across 3 ecosystems)
Debian:13(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| joserfc | 1.1.0-1 ... 1.7.4-1 (22 versions) |
| — |
Debian:14(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| joserfc | 1.1.0-1 ... 1.6.5-1 (16 versions) |
| — |
PyPI(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| joserfc | 1.3.4 ... 1.6.5 (13 versions) |
| — |
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 8× in last 7d / 33× 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.
Showing the most recent 100 of 198 refreshes on record for this CVE.
A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 98 oldest rows on record are not shown and were not checked, so the counts can still include repeats.
- 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.3% · 17th percentile
- 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.3% · 17th percentile
- 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.3% · 17th percentile
- 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.3% · 17th percentile
- 2026-10-18 03:34 UTCEG score recompute
- 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.3% · 17th percentile
- 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.3% · 17th percentile
- 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.3% · 17th percentile
- 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.3% · 17th percentile
- 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.3% · 17th percentile
- 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.3% · 16th percentile
- 2026-10-12 16:00 UTCVendor advisory
- 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 14:22 UTCEG score recompute
- 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.3% · 16th percentile
- 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.3% · 16th percentile
- 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.3% · 16th percentile
- 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.3% · 16th percentile
- 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.3% · 16th percentile
- 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.3% · 16th percentile
- 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.3% · 16th percentile
- 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.3% · 16th percentile
- 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.3% · 16th percentile
Show 75 moreShow fewer
- 2026-10-02 16:40 UTCOSV refresh
- 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.3% · 16th percentile
- 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.3% · 16th percentile
- 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.3% · 16th percentile
- 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.3% · 16th percentile
- 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.3% · 16th percentile
- 2026-09-26 00:27 UTCEPSS rescoreEPSS 0.3% · 16th percentile
- 2026-09-23 17:53 UTCEPSS rescoreEPSS 0.2% · 5th percentile
- 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.2% · 5th percentile
- 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.2% · 5th percentile
- 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.2% · 5th percentile
- 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.2% · 5th percentile
- 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.2% · 5th percentile
- 2026-09-13 14:07 UTCEG score recompute
- 2026-09-13 14:07 UTCVendor advisory
- 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.2% · 5th percentile
- 2026-09-10 09:35 UTCEPSS rescoreEPSS 0.2% · 5th percentile
- 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.2% · 5th percentile
- 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.2% · 5th percentile
- 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.2% · 5th percentile
- 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.2% · 5th percentile
- 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.2% · 5th percentile
- 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.2% · 5th percentile
- 2026-09-01 04:40 UTCEPSS rescoreEPSS 0.2% · 5th percentile
- 2026-08-30 21:14 UTCEG score recompute
- 2026-08-30 21:14 UTCVendor advisory
- 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.2% · 5th percentile
- 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.2% · 5th percentile
- 2026-08-28 21:41 UTCEPSS rescoreEPSS 0.2% · 5th percentile
- 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.2% · 5th percentile
- 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.2% · 5th percentile
- 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.2% · 5th percentile
- 2026-08-24 06:49 UTCVendor advisory
- 2026-08-23 03:52 UTCEG score recompute
- 2026-08-23 03:52 UTCVendor advisory
- 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.2% · 5th percentile
- 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.2% · 5th percentile
- 2026-08-21 11:54 UTCEG score recompute
- 2026-08-21 11:54 UTCVendor advisory
- 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.2% · 5th percentile
- 2026-08-20 09:38 UTCEG score recompute
- 2026-08-20 09:38 UTCVendor advisory
- 2026-08-19 17:04 UTCEPSS rescoreEPSS 0.2% · 5th percentile
- 2026-08-19 08:05 UTCEG score recompute
- 2026-08-19 08:05 UTCVendor advisory
- 2026-08-18 13:48 UTCEPSS rescoreEPSS 0.2% · 5th percentile
- 2026-08-17 13:47 UTCEPSS rescoreEPSS 0.2% · 5th percentile
- 2026-08-17 12:29 UTCEG score recompute
- 2026-08-17 12:29 UTCVendor advisory
- 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.2% · 5th percentile
- 2026-08-16 10:41 UTCEG score recompute
- 2026-08-16 10:41 UTCVendor advisory
- 2026-08-16 02:14 UTCEPSS rescoreEPSS 0.2% · 5th percentile
- 2026-08-15 09:08 UTCEG score recompute
- 2026-08-15 09:08 UTCVendor advisory
- 2026-08-15 01:30 UTCEPSS rescoreEPSS 0.2% · 5th percentile
- 2026-08-14 06:38 UTCEG score recompute
- 2026-08-14 06:38 UTCVendor advisory
- 2026-08-13 22:00 UTCEPSS rescoreEPSS 0.2% · 5th percentile
- 2026-08-13 05:04 UTCEG score recompute
- 2026-08-13 05:04 UTCVendor advisory
- 2026-08-12 13:51 UTCEPSS rescoreEPSS 0.2% · 5th percentile
- 2026-08-12 03:31 UTCEG score recompute
- 2026-08-12 03:31 UTCVendor advisory
- 2026-08-11 01:58 UTCEG score recompute
- 2026-08-11 01:58 UTCVendor advisory
- 2026-08-11 00:00 UTCEPSS rescoreEPSS 0.2% · 5th percentile
- 2026-08-10 00:25 UTCEG score recompute
- 2026-08-10 00:25 UTCVendor advisory
- 2026-08-09 13:46 UTCEPSS rescoreEPSS 0.2% · 5th percentile
- 2026-08-08 22:52 UTCEG score recompute
- 2026-08-08 22:52 UTCVendor advisory
- 2026-08-08 16:37 UTCEPSS rescoreEPSS 0.2% · 5th percentile
- 2026-08-07 21:17 UTCEG score recompute
- 2026-08-07 21:17 UTCVendor advisory
Related CVEs(same product + same vendor + same CWE)
Same product
5 shownPyPI:joserfc · Debian:13:joserfc
Same vendor
10 shownredhat:RHSA-2026:25039 · redhat:RHSA-2026:43038 · redhat:RHSA-2026:50340
Frequently asked(5)
What is CVE-2026-48990?
When was the CVE record for CVE-2026-48990 published?
Is CVE-2026-48990 actively exploited?
What is the CVSS score of CVE-2026-48990?
How do I remediate CVE-2026-48990?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-48990
Is Your Infrastructure Affected by CVE-2026-48990?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.