CVE-2026-16615Librest: weak random number generation in pkce implementation
- 6.8MediumCVSS base score
- 0.43%Exploitation in 30 daysEPSS · top 62% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
A flaw was found in librest. The PKCE implementation for OAuth authorization uses the GRand function from the GLib API, a cryptographically insecure pseudo-random number generator. Because the generated "code verifier" lacks sufficient cryptographic entropy, a malicious actor can reverse-engineer the pseudo-random number generator (PRNG) seed to predict or reconstruct the code verifier string, allowing an attacker to bypass PKCE protections and successfully impersonate the client during the OAuth 2.0 authorization flow.
Timeline
ID reserved
By redhat
Published
- 41 days later
· 41 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| redhatCNA (assigner) | 3.1 | Medium6.8 | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N |
| NVDNVD · Awaiting Analysis | 3.1 | Medium6.8 | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N |
- EPSS (exploitation in 30 days)
- 0.43% · top 62% of all CVEs (12 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.8.
Affected products
All versions: affected
Red Hat · Red Hat Enterprise Linux 10
- unaffected 0:0.9.1-11.el10_2.1 – < *
Red Hat · Red Hat Enterprise Linux 10.0 Extended Update Support
- unaffected 0:0.9.1-11.el10_0.1 – < *
What to do
Workaround: Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.
References
References5
- RHSA-2026:47085 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- RHSA-2026:62222 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/security/cve/CVE-2026-16615 (opens in a new tab)vdb-entryx_refsource_REDHAT
- RHBZ#2504432 (opens in a new tab)issue-trackingx_refsource_REDHAT
- https://gitlab.gnome.org/GNOME/librest/-/issues/25 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-47742 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-16615)Record last updated .