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
Elevated
8.7EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 8.7Exploit: Elevated riskExposed services: Not assessed

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
8.7HIGHmedium confidence
EG Risk
70
EG Risk 70/100

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%
EPSS PROB
0.2%
EPSS %ILE
8th
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
githubMentions a patch (unverified)🟡 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 / EcosystemFix (by version range) / 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 rangeFix by version rangeDependents
joserfc1.1.0-1 ... 1.7.4-1 (22 versions)
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
joserfc1.1.0-1 ... 1.6.5-1 (16 versions)
  • every version up to 1.6.8-1: fixed in 1.6.8-1
—
PyPI(1)
PackageVulnerable rangeFix by version rangeDependents
joserfc0.1.0 ... 1.6.7 (40 versions)
  • every version up to 1.6.8: fixed in 1.6.8
—

Weakness Classification(3)

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

Data Freshness Timeline

(refreshed 6× in last 7d / 30× 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.

Showing the most recent 100 of 134 total refreshes for this CVE.

  1. 2026-10-09 20:07 UTCEPSS rescore
  2. 2026-10-08 17:12 UTCEPSS rescore
  3. 2026-10-07 23:48 UTCEPSS rescore
  4. 2026-10-06 15:18 UTCEPSS rescore
  5. 2026-10-05 17:43 UTCEPSS rescore
  6. 2026-10-04 23:22 UTCEPSS rescore
  7. 2026-10-03 14:25 UTCEPSS rescore
  8. 2026-10-01 19:50 UTCEPSS rescore
  9. 2026-09-30 15:03 UTCEPSS rescore
  10. 2026-09-28 13:51 UTCEPSS rescore
  11. 2026-09-27 13:48 UTCEPSS rescore
  12. 2026-09-26 15:59 UTCEPSS rescore
  13. 2026-09-26 00:27 UTCEPSS rescore
  14. 2026-09-23 17:53 UTCEPSS rescore
  15. 2026-09-23 06:38 UTCEG score recompute
  16. 2026-09-23 06:38 UTCVendor advisory
  17. 2026-09-20 20:16 UTCEPSS rescore
  18. 2026-09-18 19:28 UTCEPSS rescore
  19. 2026-09-18 06:15 UTCEG score recompute
  20. 2026-09-18 06:15 UTCVendor advisory
  21. 2026-09-16 14:08 UTCEPSS rescore
  22. 2026-09-16 05:15 UTCEPSS rescore
  23. 2026-09-14 00:15 UTCEG score recompute
  24. 2026-09-14 00:15 UTCVendor advisory
  25. 2026-09-13 16:47 UTCEPSS rescore
Show 75 more
  1. 2026-09-13 08:59 UTCEG score recompute
  2. 2026-09-13 08:59 UTCVendor advisory
  3. 2026-09-12 14:16 UTCEG score recompute
  4. 2026-09-12 14:16 UTCVendor advisory
  5. 2026-09-11 14:53 UTCEPSS rescore
  6. 2026-09-10 09:35 UTCEPSS rescore
  7. 2026-09-08 22:01 UTCEPSS rescore
  8. 2026-09-07 16:01 UTCEPSS rescore
  9. 2026-09-06 14:19 UTCEG score recompute
  10. 2026-09-06 14:19 UTCVendor advisory
  11. 2026-09-06 13:47 UTCEPSS rescore
  12. 2026-09-05 23:53 UTCEG score recompute
  13. 2026-09-05 23:53 UTCVendor advisory
  14. 2026-09-04 05:06 UTCEPSS rescore
  15. 2026-09-02 14:12 UTCEPSS rescore
  16. 2026-09-01 13:54 UTCEPSS rescore
  17. 2026-09-01 04:40 UTCEPSS rescore
  18. 2026-08-30 22:43 UTCEG score recompute
  19. 2026-08-30 22:43 UTCVendor advisory
  20. 2026-08-30 19:17 UTCEPSS rescore
  21. 2026-08-30 11:22 UTCEG score recompute
  22. 2026-08-30 11:22 UTCVendor advisory
  23. 2026-08-30 01:22 UTCEPSS rescore
  24. 2026-08-28 21:41 UTCEPSS rescore
  25. 2026-08-27 22:15 UTCEG score recompute
  26. 2026-08-27 22:15 UTCVendor advisory
  27. 2026-08-27 14:25 UTCEPSS rescore
  28. 2026-08-26 14:46 UTCEPSS rescore
  29. 2026-08-25 13:49 UTCEPSS rescore
  30. 2026-08-25 13:43 UTCVendor advisory
  31. 2026-08-24 20:55 UTCEG score recompute
  32. 2026-08-24 20:55 UTCVendor advisory
  33. 2026-08-24 05:30 UTCVendor advisory
  34. 2026-08-23 18:06 UTCVendor advisory
  35. 2026-08-23 06:46 UTCEG score recompute
  36. 2026-08-23 06:46 UTCVendor advisory
  37. 2026-08-23 00:19 UTCEPSS rescore
  38. 2026-08-22 19:25 UTCVendor advisory
  39. 2026-08-22 06:27 UTCEG score recompute
  40. 2026-08-22 06:27 UTCVendor advisory
  41. 2026-08-21 23:49 UTCEPSS rescore
  42. 2026-08-21 15:47 UTCVendor advisory
  43. 2026-08-21 04:27 UTCEG score recompute
  44. 2026-08-21 04:27 UTCVendor advisory
  45. 2026-08-20 22:55 UTCEPSS rescore
  46. 2026-08-20 15:52 UTCVendor advisory
  47. 2026-08-20 04:02 UTCEG score recompute
  48. 2026-08-20 04:02 UTCVendor advisory
  49. 2026-08-19 17:04 UTCEPSS rescore
  50. 2026-08-19 08:15 UTCVendor advisory
  51. 2026-08-18 20:54 UTCEG score recompute
  52. 2026-08-18 13:48 UTCEPSS rescore
  53. 2026-08-17 14:24 UTCEG score recompute
  54. 2026-08-17 13:47 UTCEPSS rescore
  55. 2026-08-16 15:42 UTCEG score recompute
  56. 2026-08-16 14:56 UTCEPSS rescore
  57. 2026-08-16 04:22 UTCEG score recompute
  58. 2026-08-16 02:14 UTCEPSS rescore
  59. 2026-08-15 05:41 UTCEG score recompute
  60. 2026-08-15 01:30 UTCEPSS rescore
  61. 2026-08-14 07:00 UTCEG score recompute
  62. 2026-08-13 22:00 UTCEPSS rescore
  63. 2026-08-12 20:58 UTCEG score recompute
  64. 2026-08-12 13:51 UTCEPSS rescore
  65. 2026-08-11 22:17 UTCEG score recompute
  66. 2026-08-11 10:57 UTCEG score recompute
  67. 2026-08-11 00:00 UTCEPSS rescore
  68. 2026-08-10 00:57 UTCEG score recompute
  69. 2026-08-09 13:46 UTCEPSS rescore
  70. 2026-08-09 02:16 UTCEG score recompute
  71. 2026-08-08 16:37 UTCEPSS rescore
  72. 2026-08-08 03:35 UTCEG score recompute
  73. 2026-08-06 17:34 UTCEG score recompute
  74. 2026-08-06 13:47 UTCEPSS rescore
  75. 2026-08-06 06:14 UTCEG score recompute

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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 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 0.2% probability of exploitation in the next 30 days (8th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-49852?
CVE-2026-49852 has a CVSS base score of 8.7 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-49852?
A fix for CVE-2026-49852 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-49852 are linked in the Vendor Advisories panel on this page.

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