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TI-2026-79217 Aliases CVE-2026-86696GHSA-5rc7-wrfq-2h25

Unbounded atom creation from unsigned LogoutResponse status codes in esaml allows atom table exhaustion

Priority HIGH 69CWE-770Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
Present
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
No fix listed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-770.

Summary

Allocation of Resources Without Limits or Throttling vulnerability in esaml in dropbox esaml allows an unauthenticated attacker to exhaust the Erlang VM atom table and crash the node via unsigned LogoutResponse messages. esaml:status_code_map/1 in src/esaml.erl maps any StatusCode value it does not recognize to an atom with list_to_atom/1 on the last colon-separated segment of the URN. esaml_sp:validate_logout_response/2 verifies a signature only when the message carries one, so an unsigned LogoutResponse posted to the single-logout endpoint reaches esaml:decode_logout_response/1 and mints one permanent atom per distinct status value. Atoms are never reclaimed and the VM caps the atom table at about one million entries, so an attacker who posts that many distinct values aborts the node. This issue affects esaml: from 0.1.0 onward.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.0066 51st percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
dropboxesaml0.1.0 and later—No fix listedCNA
  • esaml Vendordropbox Affected 0.1.0 and later Fixed in — No fix listed CNA

CPE names CNA · 3

CPEVersionsRoleVendor
cpe:2.3:a:handnot2:esaml:*:*:*:*:*:*:*:*——handnot2
cpe:2.3:a:arekinath:esaml:*:*:*:*:*:*:*:*——arekinath
cpe:2.3:a:dropbox:esaml:*:*:*:*:*:*:*:*——dropbox
  • cpe:2.3:a:handnot2:esaml:*:*:*:*:*:*:*:* Versions — — ·handnot2
  • cpe:2.3:a:arekinath:esaml:*:*:*:*:*:*:*:* Versions — — ·arekinath
  • cpe:2.3:a:dropbox:esaml:*:*:*:*:*:*:*:* Versions — — ·dropbox

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-22 Threatist record created from CVE-2026-86696
  2. 2026-10-22 Alias added: GHSA-5rc7-wrfq-2h25
  3. 2026-10-23 Priority changed: MEDIUM → LOW
  4. 2026-10-30 CISA SSVC decision points changed
  5. 2026-10-30 Priority changed: LOW → HIGH
  6. 2026-10-31 EPSS moved to the 50th–90th percentile

References

Advisory 1

Other 4

  • TI-2026-79218 Unbounded SAML message decompression in esaml allows memory exhaustion CVSS 4.0HIGH 8.7
  • TI-2026-79203 Unbounded atom creation in esaml SAML parsing crashes Erlang nodes CVSS 4.0HIGH 8.7
  • TI-2026-38506 Missing one-time-use enforcement in Samly allows replay of SAML bearer assertions CVSS 4.0CRITICAL 9.1
  • TI-2026-38507 Missing InResponseTo validation in Samly allows acceptance of unsolicited SAML responses CVSS 4.0HIGH 7.6
  • TI-2026-23003 XXE in esaml SAML library allows local file read and potential SSRF CVSS 4.0MEDIUM 6.3

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences