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Fencer Intel
high 7.5

CVE-2026-80255 json

secure cookie attribute bypass with tab

published 2mo ago modified last mo. also EUVD-2026-72151

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 41%
public exploits
0
none known

Summary

A `Set-Cookie:` header using tab (horizontal tab, ASCII code 9) instead of space (ascii code 32) immediately before the `Secure` attribute causes curl to store the cookie without its Secure flag. The cookie might then wrongfully be sent over plaintext HTTP on subsequent requests to the same host.

Patch / fix

  • curl curl 8.14.2, 8.16.1, 8.20.1, 8.22.0
  • curl Debian 14 8.22.0-1

debian advisories DEBIAN-CVE-2026-80255

  • curl Ubuntu 26.10 8.20.0-2ubuntu11
  • curl Ubuntu 26.04 LTS 8.18.0-1ubuntu2.7

ubuntu advisories UBUNTU-CVE-2026-80255

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • curl hummingbird 1 8.22.0-0.1.hum1
  • libcurl hummingbird 1 8.22.0-0.1.hum1
  • libcurl-minimal hummingbird 1 8.22.0-0.1.hum1

red hat advisories RHSA-2026:63161

  • curl SLE Module for Basesystem 15 SP7 8.22.0-150700.7.33.1
  • curl SLES 15 SP5-LTSS, SLES 15 SP4-LTSS, SLE Micro 5.5 +8 more 8.14.1-150400.5.98.1
  • curl SLES for SAP 15 SP6, SLES 15 SP6-LTSS 8.22.0-150600.4.58.1

suse advisories SUSE-SU-2026:5069-1SUSE-SU-2026:5068-1SUSE-SU-2026:4954-1

  • curl openSUSE Tumbleweed 8.22.0-1.1

opensuse advisories openSUSE-SU-2026:11696-1

  • curl Alpine 3.24, Alpine 3.23 8.22.0-r0

alpine advisories ALPINE-CVE-2026-80255

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Is CVE-2026-80255 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-80255 updated cvss 3.7

curl: curl: Information disclosure due to secure cookie attribute bypass

  • Red Hat Satellite 6 openvox-agent
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Hardened Images curl 8.22.0-0.1.hum1, libcurl 8.22.0-0.1.hum1, libcurl-minimal 8.22.0-0.1.hum1
    fixed: vendor fix RHSA-2026:63161
  • Red Hat Confidential Compute Attestation build-of-trustee/trustee-rhel9, openshift-sandboxed-containers/osc-podvm-payload-rhel9 Red Hat Enterprise Linux 6 curl, libcurl Red Hat Enterprise Linux 7 curl, libcurl Red Hat Enterprise Linux 8 curl, libcurl, libcurl-minimal Red Hat Enterprise Linux 9 curl, rust, cargo, clippy, libcurl, rustfmt, +13 more Red Hat Enterprise Linux 10 curl, igvm, rust, snphost, trustee, s390utils
    +6 more products
    Red Hat Enterprise Linux AI (RHEL AI) 3 rust Red Hat JBoss Core Services jbcs-httpd24-curl, jbcs-httpd24-libcurl Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8, openshift/ose-rhel-coreos-9 Red Hat OpenShift Container Platform 5 openshift/ose-rhel-coreos-9 Red Hat OpenShift Dev Spaces devspaces/code-rhel9 Red Hat Satellite 6 foreman, foreman-cli, foreman-ec2, foreman-gce, puppet-agent, foreman-ovirt, +10 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
partial
Assessed
2mo ago

Exploit prediction

0.48% chance of exploitation in the next 30 days, higher than 41% of all scored CVEs (FIRST EPSS, 2026-11-11).

Exploits and checks

  • hackerone.com https://hackerone.com/reports/3972395 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CISA ADP 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected products

  • curl curl

Classification

Weakness
  • CWE-201 Insertion of Sensitive Information Into Sent Data

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.