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NVD / CVE Program· CNA EEF

CVE-2026-55952: TLS 1.3 server denial of service via malformed ClientHello pre-shared key extension

Noroxi assessment

Priority: Monitor (action score 32/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.48% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Erlang OTP 11.2.12.10, 11.6.0.3, 11.7.3.

Low priority for now. Upgrade to Erlang OTP 11.2.12.10, 11.6.0.3, 11.7.3 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

The Erlang/OTP ssl application does not validate that the PSK identity list and binder list carried in a TLS 1.3 ClientHello pre-shared key extension have equal length before passing them to the session ticket handler. In tls_handshake_1_3:handle_pre_shared_key/3, an OfferedPreSharedKeys record with a mismatched number of identities and binders is forwarded directly to tls_server_session_ticket:use/4, which crashes the session ticket handler process. An unauthenticated remote attacker can send a single crafted ClientHello to a TLS 1.3 server with session tickets enabled (stateful or stateless mode) and permanently disrupt session ticket handling on that listener. New TLS 1.3 handshakes complete but subsequently crash when the server attempts to issue a session ticket, effectively making TLS 1.3 unusable on the affected listener until the ssl application is restarted. TLS 1.2 connections are not affected. This issue affects OTP from OTP 22.2 before OTP 29.0.3, OTP 28.5.0.3 and OTP 27.3.4.14, corresponding to ssl from 9.5 before 11.7.3, 11.6.0.3 and 11.2.12.10.

HighCVSS 8.2 · v4.0—No exploit Fix available
Published
Jul 2, 2026
Updated
Oct 25, 2026
EPSS
0.4% · 41th percentile

Report tools

JSON

Action score

32

Monitor

Low priority for now.

CVSS
32 / 40 · 8.2 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.4%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · EEF
8.2
NVD has not scored this yet; the score shown is the CNA’s.

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-55952

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
erlangerlang/otp
erlangerlang/ssl

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • erlang erlang/otp22.2 and later · before 27.3.4.14
  • erlang erlang/otp28.0 and later · before 28.5.0.3
  • erlang erlang/otp29.0 and later · before 29.0.3
  • erlang erlang/ssl9.5 and later · before 11.2.12.10
  • erlang erlang/ssl11.3 and later · before 11.6.0.3
  • erlang erlang/ssl11.7 and later · before 11.7.3

Versions reported by the vendor

Affected version ranges reported by the assigning authority (EEF). Independent of NVD's CPE analysis and usually ahead of it.

  • Erlang OTP

    • 9.5 and lateraffected · otpfixed in 11.7.3, 11.6.0.3, 11.2.12.10
    • 22.2 and lateraffected · otpfixed in 29.0.3, 28.5.0.3, 27.3.4.14
    • 339a279f02ce38a7b23010e56000613e19abb21f and lateraffected · gitfixed in e77823e6d980b2ec0b4fe4ea3f2d098ca239e3ce, 2c3e599797644310e5d4aa39c7193420e59dadff, 9b5437c72fa3403a75c1aba28e5c532bc191c662

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12erlangfrom 0—
Debian:13erlangbefore 1:27.3.4.1+dfsg-1+deb13u31:27.3.4.1+dfsg-1+deb13u3
Debian:14erlangbefore 1:29.0.3+dfsg-11:29.0.3+dfsg-1
openSUSE:Tumbleweederlangbefore 28.5.0.4-1.128.5.0.4-1.1
openSUSE:Tumbleweederlang27before 27.1.3-3.127.1.3-3.1
Red Hat:hummingbird:1erlang27before 0:27.3.4.17-1.hum10:27.3.4.17-1.hum1
Red Hat:hummingbird:1erlang27-asn1before 0:27.3.4.17-1.hum10:27.3.4.17-1.hum1
Red Hat:hummingbird:1erlang27-common_testbefore 0:27.3.4.17-1.hum10:27.3.4.17-1.hum1
Red Hat:hummingbird:1erlang27-compilerbefore 0:27.3.4.17-1.hum10:27.3.4.17-1.hum1
Red Hat:hummingbird:1erlang27-cryptobefore 0:27.3.4.17-1.hum10:27.3.4.17-1.hum1
Red Hat:hummingbird:1erlang27-debuggerbefore 0:27.3.4.17-1.hum10:27.3.4.17-1.hum1
Red Hat:hummingbird:1erlang27-dialyzerbefore 0:27.3.4.17-1.hum10:27.3.4.17-1.hum1
Red Hat:hummingbird:1erlang27-diameterbefore 0:27.3.4.17-1.hum10:27.3.4.17-1.hum1
Red Hat:hummingbird:1erlang27-edocbefore 0:27.3.4.17-1.hum10:27.3.4.17-1.hum1
Red Hat:hummingbird:1erlang27-eldapbefore 0:27.3.4.17-1.hum10:27.3.4.17-1.hum1
Red Hat:hummingbird:1erlang27-erl_interfacebefore 0:27.3.4.17-1.hum10:27.3.4.17-1.hum1
Red Hat:hummingbird:1erlang27-ertsbefore 0:27.3.4.17-1.hum10:27.3.4.17-1.hum1
Red Hat:hummingbird:1erlang27-etbefore 0:27.3.4.17-1.hum10:27.3.4.17-1.hum1
Red Hat:hummingbird:1erlang27-eunitbefore 0:27.3.4.17-1.hum10:27.3.4.17-1.hum1
Red Hat:hummingbird:1erlang27-examplesbefore 0:27.3.4.17-1.hum10:27.3.4.17-1.hum1
Red Hat:hummingbird:1erlang27-ftpbefore 0:27.3.4.17-1.hum10:27.3.4.17-1.hum1
Red Hat:hummingbird:1erlang27-gdb-toolsbefore 0:27.3.4.17-1.hum10:27.3.4.17-1.hum1
Red Hat:hummingbird:1erlang27-inetsbefore 0:27.3.4.17-1.hum10:27.3.4.17-1.hum1
Red Hat:hummingbird:1erlang27-jinterfacebefore 0:27.3.4.17-1.hum10:27.3.4.17-1.hum1

+22

Same product

erlang: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-55953TLS 1.2 and DTLS client accepts unoffered anonymous cipher suite, bypassing server authentication
    36Monitor
  • CVE-2026-49759Stack buffer overflow in SCTP error cause parsing in inet_drv allows remote VM crash
    35Monitor
  • CVE-2026-59251Denial of service via exponential certificate policy tree growth in path validation
    34Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2026-54891Jul 2, 2026 · Plaintext APPLICATION_DATA injected during TLS handshake delivered to client application post-handshake in ssl
    25Monitor
  • ← EarlierCVE-2026-55950Jul 2, 2026 · DTLS listener crash via race condition in dtls_packet_demux causes denial of service for all sessions
    34Monitor
  • Later →CVE-2026-42792Jul 27, 2026 · epmd permanent DoS via EMFILE on accept(2) in erts
    25Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Erlang OTP11.2.12.10Vendor (CNA)
Erlang OTP11.6.0.3Vendor (CNA)
Erlang OTP11.7.3Vendor (CNA)
Erlang OTP27.3.4.14Vendor (CNA)
Erlang OTP28.5.0.3Vendor (CNA)
Erlang OTP29.0.3Vendor (CNA)
Erlang OTP2c3e599797644310e5d4aa39c7193420e59dadffVendor (CNA)
Erlang OTP9b5437c72fa3403a75c1aba28e5c532bc191c662Vendor (CNA)
Erlang OTPe77823e6d980b2ec0b4fe4ea3f2d098ca239e3ceVendor (CNA)
debian:erlang1:27.3.4.1+dfsg-1+deb13u3 · Debian:13Package registry (OSV)
opensuse:erlang28.5.0.4-1.1 · openSUSE:TumbleweedPackage registry (OSV)
opensuse:erlang2727.1.3-3.1 · openSUSE:TumbleweedPackage registry (OSV)
red hat:erlang270:27.3.4.17-1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:erlang27-asn10:27.3.4.17-1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:erlang27-common_test0:27.3.4.17-1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:erlang27-compiler0:27.3.4.17-1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:erlang27-crypto0:27.3.4.17-1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:erlang27-debugger0:27.3.4.17-1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:erlang27-dialyzer0:27.3.4.17-1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:erlang27-diameter0:27.3.4.17-1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:erlang27-edoc0:27.3.4.17-1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:erlang27-eldap0:27.3.4.17-1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:erlang27-erl_interface0:27.3.4.17-1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:erlang27-erts0:27.3.4.17-1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
suse:erlang23.3.4.19-150300.3.39.1 · SUSE:Linux Enterprise Module for Server Applications 15 SP7Package registry (OSV)
suse:erlang2626.2.1-150300.7.28.1 · SUSE:Linux Enterprise Module for Server Applications 15 SP7Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
Integrity
Availability
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
X

Weakness class (CWE)

CWE-1284 · Improper Validation of Specified Quantity in Input

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (6 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records