CVE-2026-54919: cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library

Routine

HIGH 7.4REMOTEUPGRADE

CVE-2026-54919 is a high-severity flaw (CVSS 7.4) affecting cpp-httplib. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. In affected Mbed TLS backend versions from 0.31.0 through 0.46.1 and wolfSSL backend versions from 0.33.0 through 0.46.1, when cpp-httplib is built with CPPHTTPLIB_MBEDTLS_SUPPORT or CPPHTTPLIB_WOLFSSL_SUPPORT and a client connects to an IP-literal host with server certificate verification enabled, SSLClient and Client in HTTPS mode skip certificate chain validation

Why this priority

High severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.4 (High)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	0.3% (top 82%)
CISA exploited list	No
Weakness	CWE-295
Published	2026-07-10
Last modified	2026-10-25

Publisher (CNA): GitHub, Inc. · Vendor: yhirose

Last updated 2026-10-25 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-10 17:16 UTCPublished CVE record published
2026-10-25 15:10 UTCUpdated Record last modified

yhirose cpp-httplib UPGRADE

Affected: >= 0.31.0 and < 0.47.0

Fixed in: 0.47.0

Safe to downgrade to: a release before 0.31.0

1. Check installed version

apt-cache policy cpp-httplib || rpm -q cpp-httplib || cpp-httplib --version

2. UPGRADE to 0.47.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade cpp-httplib

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade cpp-httplib

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 0.31.0 (Debian / Ubuntu)

apt-cache madison cpp-httplib sudo apt install cpp-httplib=<VERSION_BEFORE_0.31.0> sudo apt-mark hold cpp-httplib

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list cpp-httplib sudo dnf downgrade cpp-httplib-<VERSION_BEFORE_0.31.0> sudo dnf versionlock add cpp-httplib

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-54919?

cpp-httplib: upgrade to 0.47.0. Exact commands for each OS are on this page.

Is CVE-2026-54919 being exploited?

CVE-2026-54919 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-54919 affect?

CVE-2026-54919 affects cpp-httplib. Severity is high (CVSS 7.4). cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. In affected Mbed TLS backend versions from 0.31.0 through 0.46.1 and wolfSSL backend versions from 0.33.0 through 0.46.1, when cpp-httplib is built with CPPHT

How urgent is CVE-2026-54919?

Priority 35/100. High severity; Remotely exploitable, no login, no user action

Software pages

wolfSSL vulnerabilities

References

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