CVE-2021-42697

mediumpriority · attend · 53EPSS 0.361 · 98 %ileexploit · PoCEUUS

grimoire priorityP1 · Urgent

Exploitable?

Public exploit

2 exploits · PoC

Likely / severe?

36.1% (98th) EPSS

CVSS 5 · medium

Is it mine?

12 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · nvd · osv

EPSS · scored 2026-10-22

Akka HTTP 10.1.x before 10.1.15 and 10.2.x before 10.2.7 can encounter stack exhaustion while parsing HTTP headers, which allows a remote attacker to conduct a Denial of Service attack by sending a User-Agent header with deeply nested comments.

cvss

Technical severity, 0–10. One row per scoring source.

7.5

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 5–7.5

v2.05mediumAV:N/AC:L/Au:N/C:N/I:N/A:Pprimary · NVD / NIST USexploitability 10 · impact 2.9

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hprimary · NVD / NIST USexploitability 3.9 · impact 3.6

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · OSV

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:Hsecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-674USprimaryCWE-674USCWE-787US

exploits (2)

Public proof-of-concept and weaponised exploit code.

affected products (12)

Products and version ranges known to be affected.

n/a n/a≤ n/aenisa_euvdEU
akka http server10.1.0 → 10.1.15nvdUScpe:2.3:a:akka:http_server:*:*:*:*:*:*:*:*
akka http server10.2.0 → 10.2.7nvdUScpe:2.3:a:akka:http_server:*:*:*:*:*:*:*:*
Maven com.typesafe.akka:aakka-http-core_2.13.0-M3≥ 10.1.0osvUSpkg:maven/com.typesafe.akka/aakka-http-core_2.13.0-M3
Maven com.typesafe.akka:akka-http-core_2.1110.1.0 → 10.1.15osvUSpkg:maven/com.typesafe.akka/akka-http-core_2.11
Maven com.typesafe.akka:akka-http-core_2.1210.1.0 → 10.1.15osvUSpkg:maven/com.typesafe.akka/akka-http-core_2.12
Maven com.typesafe.akka:akka-http-core_2.1210.2.0-M1 → 10.2.7osvUSpkg:maven/com.typesafe.akka/akka-http-core_2.12
Maven com.typesafe.akka:akka-http-core_2.1310.1.0 → 10.1.15osvUSpkg:maven/com.typesafe.akka/akka-http-core_2.13
Maven com.typesafe.akka:akka-http-core_2.1310.2.0-M1 → 10.2.7osvUSpkg:maven/com.typesafe.akka/akka-http-core_2.13
Maven com.typesafe.akka:akka-http-core_2.13.0-M5≥ 10.1.0osvUSpkg:maven/com.typesafe.akka/akka-http-core_2.13.0-M5
Maven com.typesafe.akka:akka-http-core_2.13.0-RC2≥ 10.1.0osvUSpkg:maven/com.typesafe.akka/akka-http-core_2.13.0-RC2
Maven com.typesafe.akka:akka-http-core_2.13.0-RC3≥ 10.1.0osvUSpkg:maven/com.typesafe.akka/akka-http-core_2.13.0-RC3

advisories (1)

Vendor and ecosystem advisories describing this.

GHSA-3hw2-h67c-wq66Uncontrolled Recursion in Akka HTTP2022-05-24ghsa · osvUS
Akka HTTP 10.1.x and 10.2.x before 10.2.7 can encounter stack exhaustion while parsing HTTP headers, which allows a remote attacker to conduct a Denial of Service attack by sending a User-Agent header with deeply nested comments.

also known as (3)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd nvd osv NVD CVE.org MITRE

published 2021-11-02modified 2026-06-17

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Related entries.

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+712 more

references (18)

External citations — patches, advisories, analysis.

scry

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