CVE-2026-48990Disclosure

LOWCVSS 5.3 · MEDIUM

Signal is active with 1 mentions in latest observed window

Immediate actions

  • Track advisory updates for patch or workaround availability

Recommended action window: Monitor and triage in normal cycle

NVD description

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.

0.0/ 10 priority

Sources & remediation

Weakness type (CWE)
CWE-400CWE-770

Priority

LOW

Exploitation

NONE

PoC

NONE

Patch

NONE

Momentum

NONE

Threat summary

  • 1 mentions across 1 observed day

What's happening

  • Technical details provided in 1 signal
  • Disclosure: 1 classified signal
  • 1 total mentions across 1 day

Deep dive

Activity timeline1 mentions / 1d
00111Mentions · 2026-06-26: 1Technical Details · 2026-06-26: 106-26
Signal classification1 categories
Disclosure
1100.0%
Referenced assets1 URL
Full discourse1 post
  • DailyCVE@dailycve
    Disclosure

    🔵 joserfc: b64=false RFC7797 JWS payloads bypass JWSRegistry payload-size limits during deserialization (#CVE-2026-48990) -DC-Jun2026-699 https://dailycve.com/joserfc-b64false-rfc7797-jws-payloads-bypass-jwsregistry-payload-size-limits-during-deserialization-cve-2026-48990-dc-jun2026-699/

    Post summary

    The tweet announces CVE‑2026‑48990, noting that JWS payloads with b64=false can bypass JWSRegistry payload‑size limits during deserialization.

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    216 followersView on X

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