CVE-2026-45372

criticalpriority · track · 0EPSS 0.004 · 34 %ileEURUUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

0.41% (34th) EPSS

CVSS 9.9 · critical

Is it mine?

5 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · fstec_bdu · nvd

EPSS · scored 2026-10-24

cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to 0.44.0, when cpp-httplib's server parses an incoming request, it applies percent-decoding to every header value except Location and Referer. The validity check (is_field_value) is run before decoding, so encoded %0D%0A passes the check and is then expanded to a literal \r\n byte pair inside the stored header value. This vulnerability is fixed in 0.44.0.

cvss

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

9.9

010

base score 0–10 · higher = more severe · hover a vector to decode

v3.19.9criticalAV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:Lsecondary · FSTEC (BDU) RU

v3.19.9criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:Lsecondary · ENISA EU

v3.19.9criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:Lsecondary · security-advisories@github.comexploitability 3.9 · impact 5.3

v3.19.1criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:L/E:Usecondary · CVSS-BT (t0sche)

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: poc · Automatable: yes · Technical Impact: partialcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-444USCWE-444USCWE-93USCWE-93US

affected products (5)

Products and version ranges known to be affected.

yhirose cpp-httplib≤ < 0.44.0enisa_euvdEU
Сообщество свободного программного обеспечения Debian GNU/Linux≤ 13fstec_bduRU
Сообщество свободного программного обеспечения Debian GNU/Linux≤ 12fstec_bduRU
Сообщество свободного программного обеспечения cpp-httplib≤ 0.44.0fstec_bduRU
yhirose cpp-httplib< 0.44.0nvdUScpe:2.3:a:yhirose:cpp-httplib:*:*:*:*:*:*:*:*

also known as (3)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu nvd NVD CVE.org MITRE

published 2026-05-29modified 2026-07-22

references (4)

External citations — patches, advisories, analysis.

scry

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