CVE-2026-49852

HIGHPre-NVD 8.78.7—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.7 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2%, top 91% 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, secondary
Trending — 3 sources updated this weekElevated
8.7EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.7Exploit: Elevated riskExposed: 0

A fix is available — apply it.

joserfc is a Python library that provides an implementation of several JSON Object Signing and Encryption (JOSE) standards. Prior to 1.6.8, joserfc.jwt.decode accepts attacker-forged HMAC-signed tokens when the caller-supplied verification key is the empty string or None, because HMACAlgorithm.sign and HMACAlgorithm.verify in src/joserfc/_rfc7518/jws_algs.py pass the output of OctKey.get_op_key(...) to hmac.new(...) and OctKey.import_key in src/joserfc/_rfc7518/oct_key.py only emits a SecurityWarning for keys shorter than 14 bytes without rejecting zero-length input. This issue is fixed in version 1.6.8.

CVSS v3
8.7
EG Score
8.7(medium)
EG Risk
70(Attend)
EG Risk 70/100SSVC: Attend

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
Severity87% × 45%
Exploitation40% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
0%
EPSS %ILE
9%
KEV
Not listed

Published

July 2, 2026

Last Modified

July 23, 2026

Advisory Details (3)

Auto-updated Jul 17, 2026
🔬 Proof of concept available. Patch available. Sources: github, github_commit, github_release.
github_release Patch Available

1.6.8

Patch available: authlib/joserfc 1.6.8

https://github.com/authlib/joserfc/releases/tag/1.6.8
github_commit Patch Available

commit 86d00910b2b2 (authlib/joserfc)

Patch available: authlib/joserfc 1.6.8 (contains commit 86d00910b2b2)

https://github.com/authlib/joserfc/commit/86d00910b2b2d2d07503fee9b572906daefab7f1
github Patch Available🟡 PoC Available

joserfc: HS256/HS384/HS512 verify accepts empty/nil HMAC key (cross-language sibling of CVE-2026-45363) · Advisory · authlib/joserfc · GitHub

https://github.com/authlib/joserfc/security/advisories/GHSA-gg9x-qcx2-xmrh

Vendor Advisories for CVE-2026-49852(2)

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

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatjaeger-main-2.19.0-1.2.hum12026-07-20redhat

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)
PackageVulnerable rangeFixed inDependents
joserfc1.1.0-1 ... 1.7.4-1 (22 versions)——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
joserfc1.1.0-1 ... 1.6.5-1 (16 versions)1.6.8-1—
PyPI(1)
PackageVulnerable rangeFixed inDependents
joserfc0.1.0 ... 1.6.7 (40 versions)1.6.8—

Weakness Classification(3)

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

Data Freshness Timeline

(refreshed 22× in last 7d / 64× 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. 2026-08-25 13:49 UTCEPSS rescore
  2. 2026-08-25 13:43 UTCVendor advisory
  3. 2026-08-24 20:55 UTCEG score recompute
  4. 2026-08-24 20:55 UTCVendor advisory
  5. 2026-08-24 05:30 UTCVendor advisory
  6. 2026-08-23 18:06 UTCVendor advisory
  7. 2026-08-23 06:46 UTCEG score recompute
  8. 2026-08-23 06:46 UTCVendor advisory
  9. 2026-08-23 00:19 UTCEPSS rescore
  10. 2026-08-22 19:25 UTCVendor advisory
  11. 2026-08-22 06:27 UTCEG score recompute
  12. 2026-08-22 06:27 UTCVendor advisory
  13. 2026-08-21 23:49 UTCEPSS rescore
  14. 2026-08-21 15:47 UTCVendor advisory
  15. 2026-08-21 04:27 UTCEG score recompute
  16. 2026-08-21 04:27 UTCVendor advisory
  17. 2026-08-20 22:55 UTCEPSS rescore
  18. 2026-08-20 15:52 UTCVendor advisory
  19. 2026-08-20 04:02 UTCEG score recompute
  20. 2026-08-20 04:02 UTCVendor advisory
  21. 2026-08-19 17:04 UTCEPSS rescore
  22. 2026-08-19 08:15 UTCVendor advisory
  23. 2026-08-18 20:54 UTCEG score recompute
  24. 2026-08-18 13:48 UTCEPSS rescore
  25. 2026-08-17 14:24 UTCEG score recompute
Show 56 more
  1. 2026-08-17 13:47 UTCEPSS rescore
  2. 2026-08-16 15:42 UTCEG score recompute
  3. 2026-08-16 14:56 UTCEPSS rescore
  4. 2026-08-16 04:22 UTCEG score recompute
  5. 2026-08-16 02:14 UTCEPSS rescore
  6. 2026-08-15 05:41 UTCEG score recompute
  7. 2026-08-15 01:30 UTCEPSS rescore
  8. 2026-08-14 07:00 UTCEG score recompute
  9. 2026-08-13 22:00 UTCEPSS rescore
  10. 2026-08-12 20:58 UTCEG score recompute
  11. 2026-08-12 13:51 UTCEPSS rescore
  12. 2026-08-11 22:17 UTCEG score recompute
  13. 2026-08-11 10:57 UTCEG score recompute
  14. 2026-08-11 00:00 UTCEPSS rescore
  15. 2026-08-10 00:57 UTCEG score recompute
  16. 2026-08-09 13:46 UTCEPSS rescore
  17. 2026-08-09 02:16 UTCEG score recompute
  18. 2026-08-08 16:37 UTCEPSS rescore
  19. 2026-08-08 03:35 UTCEG score recompute
  20. 2026-08-06 17:34 UTCEG score recompute
  21. 2026-08-06 13:47 UTCEPSS rescore
  22. 2026-08-06 06:14 UTCEG score recompute
  23. 2026-08-05 19:17 UTCEPSS rescore
  24. 2026-08-04 19:57 UTCEG score recompute
  25. 2026-08-04 15:10 UTCEPSS rescore
  26. 2026-08-04 10:39 UTCEPSS rescore
  27. 2026-08-03 19:02 UTCEG score recompute
  28. 2026-08-03 10:36 UTCEPSS rescore
  29. 2026-08-02 08:34 UTCEG score recompute
  30. 2026-08-02 02:27 UTCEPSS rescore
  31. 2026-08-01 09:52 UTCEG score recompute
  32. 2026-08-01 04:16 UTCEPSS rescore
  33. 2026-07-30 23:37 UTCEG score recompute
  34. 2026-07-30 16:28 UTCEPSS rescore
  35. 2026-07-30 12:16 UTCEG score recompute
  36. 2026-07-30 01:30 UTCEPSS rescore
  37. 2026-07-29 02:02 UTCEG score recompute
  38. 2026-07-28 15:37 UTCEPSS rescore
  39. 2026-07-27 15:52 UTCEG score recompute
  40. 2026-07-26 16:35 UTCEG score recompute
  41. 2026-07-26 14:54 UTCEPSS rescore
  42. 2026-07-26 05:10 UTCEG score recompute
  43. 2026-07-25 14:18 UTCEPSS rescore
  44. 2026-07-24 14:18 UTCEPSS rescore
  45. 2026-07-23 14:18 UTCEPSS rescore
  46. 2026-07-23 03:18 UTCEG score recompute
  47. 2026-07-22 14:08 UTCEPSS rescore
  48. 2026-07-21 15:25 UTCEPSS rescore
  49. 2026-07-20 17:08 UTCEPSS rescore
  50. 2026-07-19 14:31 UTCEPSS rescore
  51. 2026-07-19 14:31 UTCEPSS rescore
  52. 2026-07-19 03:51 UTCEG score recompute
  53. 2026-07-19 02:29 UTCEPSS rescore
  54. 2026-07-17 19:26 UTCEG score recompute▲ 8.70
  55. 2026-07-17 19:24 UTCMITRE cvelistV5CVSS v3 → 8.7 · CVSS v4 → 8.7
  56. 2026-07-02 20:07 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-49852?
CVE-2026-49852 is a high vulnerability published on July 2, 2026. joserfc is a Python library that provides an implementation of several JSON Object Signing and Encryption (JOSE) standards. Prior to 1.6.8, joserfc.jwt.decode accepts attacker-forged HMAC-signed tokens when the caller-supplied verification key is the empty string or None, because HMACAlgorithm.sign…
When was CVE-2026-49852 disclosed?
CVE-2026-49852 was first published in the National Vulnerability Database on July 2, 2026, with the most recent update on July 23, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-49852 actively exploited?
CVE-2026-49852 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 90.9% of all scored CVEs.
What is the CVSS score of CVE-2026-49852?
CVE-2026-49852 has a CVSS v3 base score of 8.7 (NVD).
How do I remediate CVE-2026-49852?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-49852, 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

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