CVE-2026-32689: Phoenix · Long-poll NDJSON body splitting causes large memory allocation
Affects phoenixSource GCVE Database
Not known to be exploited · CVSS 8.7 High : upgrade to 1.7.22 soon.
Data as of 27 Oct 2026, 00:07 UTC
- Patch
- Available – fixed in 1.7.22, 1.8.6
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 5 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade phoenix to 1.7.22; phoenix to 1.8.6.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Hexphoenix | Affected
| Fixed in
|
| Hexphoenix | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
### Summary An unauthenticated denial-of-service vulnerability in Phoenix's long-poll transport allows a remote client to allocate a large amount of memory with a HTTP request. A handful of concurrent requests can be sufficient to let the node run out of memory. See also https://cna.erlef.org/cves/CVE-2026-32689.html. ### Details The unoptimised code path exists on the `application/x-ndjson` POST handling in the LongPoll transport. The endpoint requires only a session token, which any client can obtain by issuing a GET to the same URL with a matching `Origin` header, so exploitation is unauthenticated. ### Impact Anyone who runs a LiveView app with a public Longpoll socket or uses a `Phoenix.Socket` with longpoll option. Longpoll has been enabled for newly generated Phoenix projects since Phoenix 1.7.11.
References
- github.com/phoenixframework/phoenix/security/advisories/GHSA-628h-q48j-jr6q (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-32689 (opens in a new tab)
- github.com/phoenixframework/phoenix/commit/1a67c61ff9ce0a7711662ac7354861917a7c80f7 (opens in a new tab)
- github.com/phoenixframework/phoenix/commit/912ea181fd247c21dbcc49fb97d0053b947d81bf (opens in a new tab)
- cna.erlef.org/cves/CVE-2026-32689.html (opens in a new tab)
- github.com/phoenixframework/phoenix (opens in a new tab)
- osv.dev/vulnerability/EEF-CVE-2026-32689 (opens in a new tab)